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HEADQUARTERS
U.S. Army Information Systems Engineering Command Fort Huachuca, Arizona 85613-5300 |
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HEADQUARTERS
U.S. Army Information Systems Engineering Command Fort Huachuca, Arizona 85613-5300 |
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Automated Information System (AIS)
Design Guidance
Long-Haul Transmission Systems
The following chapter provides a general reference for applicable DoD and industry standards, architectures, and systems that define the context for AIS long-haul transmission systems. A short summary paragraph is provided for each with the appropriate hot link uniform resource locator (URL) provided for additional detail if available. This chapter is primarily provided for reference and definition purposes.
The National Military Strategy relies on power projection by highly flexible, rapid response, tailored-force packages under Joint Task Force (JTF) or Combined Task Force (CTF) command. These force packages will support a spectrum of military and political responses to promote national interests worldwide. The National Military Strategy dictates that U.S. forces be structured to project power from Continental United States (CONUS) bases, sanctuary locations, and in-theater locations to an area of conflict anywhere in the world.
The new warfighting context outlined in the National Military Strategy drives the evolution of a concept to guide all Services toward a global Command, Control, Communications, Computers, and Intelligence (C4I) "Infosphere." C4I for the Warrior (C4IFTW) architectures are being designed to provide an information infrastructure that is transparent to the warriors but accessible by them anywhere they are deployed. The warriors will be supported by integrated media services--voice, data, and video. Based on asynchronous transfer mode (ATM), Synchronous Optical Network (SONET), and integrated services digital network (ISDN) technologies, the early deployment of tactical broadband ISDN (B-ISDN) transmission networks is critical.
Future JTF tactical communications must be flexible, modular, integrated, lightweight, and rapidly deployable. Strategic Defense Information Infrastructure (DII) and JTF connectivity shows the notional connectivity from the perspective of the interface between the strategic and tactical environments. The DII interfaces with the JTF area at the DISN nodes. The DII is a seamless web of communications networks, computers, software, data bases, applications, and other capabilities that meet the information processing and transport needs of DoD users in peacetime and in crisis, conflict, humanitarian support, and wartime roles. The Army must design, engineer and implement its long-haul transmission systems to be in compliance and ensure this seamless web.
STRATEGIC DII AND JTF CONNECTIVITY
The vision of C4IFTW is to provide the warrior with a fused, real-time, true representation of the three-dimensional battlespace and the ability to coordinate in all directions. The key information system capabilities needed to respond to the deployed warfighter include:
Army systems are being developed and/or converted to run on a common technical architecture that has been defined for all DoD processors, servers, and communications services. The TRM for Information Management is the initial effort to bring commonality and standardization to DoD's technical infrastructure. This technical model is intentionally generalized and does not imply any specific system architecture. Its purpose is to provide a "set of concepts, entities, interfaces, and diagrams that provides a basis for the specification of standards."
The TRM adopts foundation work of the Institute of Electrical and Electronics Engineers (IEEE) Draft Guide to Portable Operating System Interface for Computer Environments (POSIX) Open Systems Environment (OSE) (see IEEE P1003.0: Guide to the POSIX Open Systems Environment) and it identifies services for the Application Platform Entity of the POSIX Open Systems Reference Model. It identifies application program interfaces (API) such as system services, communication services, information services, and human-computer interaction services between the Application Platform Entity and the Application Software Entity. It also identifies external environment interfaces (EEI) such as communications services, information services, and human-computer interaction services between the Application Platform Entity and the external environment.
The DoD JTA draws on the TAFIM, which provides general guidance and documents the processes and framework for defining the JTA and other technical architectures. The TAFIM applies to many DoD mission/domain areas and lists all adopted information technology standards that promote interoperability, portability, and scalability.
The DII Master Plan is a tool to manage the evolution of the DII. The descriptive and analytical data for the DII will be available at several levels of detail.
The purposes of the DII Master Plan are to:
The DII COE details the technical and functional requirements for a common operating environment for information support to the warfighter. It identifies classes of functions common to all or most application components.
The development of the DII COE stems from the Global Command and Control System (GCCS) COE effort and is perhaps the most significant and useful technical by-product of the GCCS development effort. As an outgrowth of this effort the Services have agreed to migrate their Command and Control (C2) systems to the DII COE.
The areas of concern for long-haul transmission systems are identified in the "Comm Links" ellipse in the following figure.
DEFENSE INFORMATION INFRASTRUCTURE
COMMON OPERATING ENVIRONMENT
The JTA is the baseline for DoD systems design guidance. It identifies a common set of mandatory information technology standards and guidelines to be used in all new and upgraded systems across DoD. The scope of the JTA is focused on Command, Control, and Intelligence (C2I) systems (to include sustaining base systems, combat support information systems, and office automation systems), the communications and computers that directly support the C4I, and the interfaces of those systems with other key assets (e.g., weapon systems, sensors, models, and simulations) to support critical joint warfighter interoperability.
The JTA draws on the TAFIM, which provides general guidance and documents the processes and framework for defining the JTA and other technical architectures. The JTA necessarily includes requirements related to interoperability by identifying the minimum set of standards.
The standards and specifications identified in the JTA are entirely consistent with and support the DoD Standards and Acquisition Reform initiatives. The DoD standards policy recognizes the need for DoD to specify interface standards that are required for interoperability. The standards in the JTA are almost entirely performance-based interface standards. Most are commercial standards. None of the military standards require a waiver to use.
The JTA is a forward-looking document, defining the standards to which to build new and upgraded systems. The intent is to indicate migration direction. Existing systems are not expected to conform immediately to the JTA. When these systems are upgraded, the JTA will be used to transition the system toward a common interoperability goal. If legacy standards are needed to interface to existing systems they can be implemented with appropriate approval in addition to the mandated standard.
The purpose of the AITS (see TAFIM, Volume 7) is to guide DoD enterprise acquisition and migration of legacy systems by providing a definitive set of Information Technology (IT) standards to be used in the DoD. These standards provide the enterprise-level integration guidance described in the TAFIM DoD Information Management (IM) Integration Model, Volume 1, Chapter 5.
The ITSG provides the foundation for the AITS. It contains detailed information about the varying standards available for each of the base subject areas listed in the AITS.
The DISA core mission is DISN, GCCS, GCSS, and Defense Message System (DMS). They are "to plan, engineer, develop, test, manage programs, acquire, implement, operate, and maintain information systems for C4I and mission support under all conditions of peace and war". DISA is the DoD agency responsible for information technology. The area of concern for this guide is the DISN.
The DISN is the DoD's consolidated worldwide enterprise-level telecommunications infrastructure that provides the end-to-end information transfer network for supporting military operations, national defense C3I requirements, and corporate defense requirements. DISN is the communication transport piece of the DII, whose vision is of a widely distributed, user-driven infrastructure into which the warrior can gain access from any location for all required information. The DISN is structured to satisfy requirements that are evolving in response to changing military strategy, changing threat conditions, and advances in information and communications technology. (Select here to link to a list of available DISN documents.)
The DISN will provide the warfighter with a full range of Government-controlled and secure information transfer services for exchanging voice, video, data, and imagery to support warfighter requirements in the 21st Century.
The DISN as described in CJCSI 6211.02(3), dated 23 June 1993, Defense Information System Network and Connected Systems, includes point-to-point transmission, switched data services, video teleconferencing, etc. The CJCSI directs all Services/Agencies (S/A) to submit all long-haul communication requirements to DISA for provisioning on the DISN.
The goal DISN architecture represents a graceful technological evolution from the use of networks and systems that are owned and operated by the DoD to the use of commodity services wherever possible. A possible source of these commodity services may be the Federal Telecommunications System - 2000 (FTS2000) and its replacement, the Post-FTS2000 (PF2K), based upon service availability, satisfaction of operational and technical requirements, and cost.
DISN is the subset of the DII that primarily provides information transport services both within the DII and across DII boundaries. The DISN infrastructure encompasses a CONUS sustaining base segment, segments outside CONUS (OCONUS) in the European and Pacific theaters, a space segment, and a deployable capability. It spans strategic, space, and tactical arenas. The DISN provides seamless and interoperable information transport across strategic and tactical networks, JTFs and CTFs, as well as the telecommunication networks of non-defense departments and agencies.
The DISN strategy maximizes the use of commodity services, commercial-off-the-shelf (COTS) and Government-off-the-shelf (GOTS) technology, and international commercial standards to facilitate interoperability with the Military Services and Defense Agencies as well as with other agencies of the U.S. Government and its allies. In implementing the first phase of the goal architecture, DISA will capitalize on the efforts and resources previously expended in establishing the DISN router networks and the DISN multiplexer network (multiplexer consolidation).
The integrated worldwide telecommunications capability will support transmission of voice, data, imagery, and video at all security classification levels. The network will support flexible and rapid provisioning, be easily extended, and capable of easily accepting future technology insertions. It will also provide seamless interfaces to commercial networks as required to support increased traffic during surge and contingency conditions. The network will be capable of rapid restoral in order to minimize the necessity for independent/stand-alone operations.
The network will support the requirement for the exponential increase in bandwidth, especially in support of modeling, imagery, and video teleconferencing requirements.
The network will integrate satellite, airborne, and terrestrial-based (wire and wireless) transmission and switching systems (strategic and tactical) and provide for end-to-end visibility to support integrated management of the network and connected systems.
The transmission and backbone switching systems of the Defense Communications System form the baseline for the starting point of DISN. The Defense Communications System, often alternatively referred to as DISN legacy systems, provides network management, core telecommunications, messaging, video teleconferencing, and support services to deployed forces and mission support organizations worldwide today. The following list, organized to a large extent into categories by type of communication service, provides the geographical coverage and classification for information transported by the various Defense Communications System components.
Defense Red Switch Network (DRSN) (Classified) - Global.
Defense Switched Network (DSN) (Unclassified) - Global.
DDN (Classified/Unclassified) - Global.
- MILNET (Unclassified) - Global.
- DSNET-1, 2, and 3 (Secret, Top Secret (TS), and TS/SCI, respectively - Global.
DISN IP Router Networks.
- NIPRNET - Global.
- SIPRNET - Global (Note: SIPRNET provides transport for the Top Secret Support System (TSSS).
Joint Worldwide Intelligence Communications System (JWICS) (TS/SCI) - Global.
Defense Commercial Telecommunications Network (DCTN) Video Teleconferencing System (VTS) (Unclassified) - CONUS and Pacific.
Pacific Video Teleconferencing (PACTC) Network - (Classified) - Pacific.
Secure Video Teleconferencing System (SVTS) (Classified) - CONUS.
Digital Europe Backbone (DEB) - Europe.
European Integrated Digital Network Exchange (IDNX) Network (includes the Defense Communications Systems (DCS) Spain/Italy Reconfiguration (DSIR)) - Europe.
Defense Satellite Communications System (DSCS) - Global.
Data Transmission Network (DTN) - Global.
Hawaii Area Wideband System (HAWS) - Pacific.
Japan Reconfiguration and Digitization (JRD) Program - Pacific.
Fiber Optic Communications System in Korea (FOCSIK) - Pacific.
Pacific Consolidated Telecommunications Network (PCTN) - Pacific.
Panama Area Wideband System (PAWS) - CONUS.
Puerto Rico Area Wideband System (PRAWS) - CONUS.
Southwest Asia Transmission System (SATS) - Europe.
Washington Area Wideband System (WAWS) - CONUS.
Defense Mediterranean Improvement Program (DMIP) - Europe.
Point-to-Point Circuits - Global.
Extended Korea Improvement Project (EKIP) - Pacific.
A DISN Transition Implementation Plan (TIP) has been developed to describe at a high level the steps currently identified as necessary to implement the DISN in CONUS.
The DISN CONUS TIP is one component of an overall DISN program document tree with each of the DISN Program Management Plans (PMP) to have a standard set of attachments. The DISN in CONUS will support the global DISN requirements. The following requirements are stated in the DISN Mission Need Statement (MNS), dated 30 March 1995, from the Joint Requirements Oversight Council:
Based on the requirements and objectives in the MNS, the following are the critical system characteristics as stated in the Joint Capstone Requirements Document (JCRD) for the Defense Information System Network (DISN), draft, dated 1 January 1996:
DISA is in the process of selecting the sources for the DISN CONUS contracts. The DISN Transition Contract (DTC) will replace the DCTN contract that was scheduled to expire in February 1996. The DCTN provided CONUS voice, data, and video services. DTC provides a continuation of comparable services until the DISN service contracts are awarded, their corresponding services are implemented, tested, and accepted, and the DTC services have been fully cut over. The DTC will provide crossover circuits between the DTC network and the network implemented via the DSCS as well as interface, signaling, and numbering translation capabilities.
DISA is implementing the current increment of DISN CONUS through award of the following commercial contracts.
a. DISN Support Services - Global (DSS-G) - The DSS-G contract provides integration, technical, programmatic, and operations support for the DISN worldwide. DISA will order support services from this contract on a delivery order basis with specifically defined performance requirements and schedules. The DoD, Services, and Agencies may acquire support services under this contract through DISA in support of their DISN-related telecommunication requirements.
b. DISN Switched/Bandwidth Manager Services - CONUS (DS/BMS-C) - The DS/BMS-C contract will provide the capability to switch DISN CONUS circuit switched traffic and will provide dedicated Bandwidth Managers (BWM) in the vicinity of DISA-specified locations. The DS/BMS-C contractor will perform the active network management functions for DISN and share network coordinating information with the other DISN Service Contractors and the DISN CONUS RCC. The Initial Operational Capability (IOC) for the DS/BMS-C contract is specified as 15 January 1997.
c. DISN Transmission Services - CONUS (DTS-C) - The DTS-C contracts comprise up to nine awards - one for the backbone transmission and eight for local access in eight separate DISA areas.
The single backbone transmission service contract will provide a SONET-based, wide band backbone, network-level transport that will interconnect the BWMs provided under the DS/BMS-C contract. The access transmission service contracts will provide access between DoD facilities and the DISN CONUS backbone network. Each DoD facility will be connected to a BWM provided under the DS/BMS-C contract.
d. DISN Video Services - Global (DVS-G) - The DVS-G contractor will provide dedicated and multi-point dial-up video services. The service will include three video hubs located either at Government facilities or contractor sites. Dial-up video services requiring multipoint support will be routed to the video network hubs through the circuit switched services provided under DS/BMS-C.
DISA is in the process of acquiring a new contract for DISN Pacific communication services. The DISN TS-PAC network is being designed to serve, but not be limited to, Alaska, Hawaii, Guam, Korea, Australia, Wake Island, Diego Garcia, Okinawa, Singapore, Johnson Island, Kwajalein, the Philippines, and Japan at bandwidths ranging from T1 to SONET circuits running at OC-48.
Because of the vast distances involved in the Pacific area of operations, DISA envisions using every conceivable form of satellite communications to satisfy its requirements, ranging from well-established geostationary satellite systems operated by the International Telecommunications Satellite Organization (Intelsat) to low Earth orbit satellite services such as the Iridium system conceived and backed by Motorola Corporation.
Regional geostationary satellite systems, as well as Pentagon-owned and operated military strategic and tactical relay (MILSTAR) satellites, will also play a role in DISN TS-PAC. DISA has indicated it plans to use fiber-optic cable to provide high-speed SONET service to as many end points in the DISN TS-PAC network as possible.
Once DISN gets the DISN TS-PAC procurement underway it plans to launch a DISN Europe (DISN-EUR) procurement, with predictions of a draft request for proposals (RFP) before the end of 1997. DISA wants to structure the DISN-EUR contract to be in place to take advantage of the deregulation of communications in the European Community that will occur in 1998.
Constrained bandwidth resources, additional expenses of OCONUS operations, host nation agreements (HNA), expansive areas of responsibility (AOR), and dual-path routing requirements influence systems performance to service delivery points (SDP). There are numerous opportunities for circuit bundling, efficient use of transmission capacity, and bandwidth management to provide a wide range of cost-effective, customer-required services.
The European strategy will be characterized by replacement or upgrades of switching equipment to provide modern and maintainable multifunction switching capabilities. More competitive market pricing within the European Community may reduce bandwidth costs and further weight the requirement for bandwidth managers.
DISA plans to award its long-haul transmission service contracts for Panama, SWA, and other locations in the future. Panama, South America, and the Caribbean are not clearly shown as belonging to any of the regional areas: CONUS, PACIFIC, EUROPE, and SWA. The United States Southern Command (USSOUTHCOM) AOR will be managed together with the DISN-CONUS region and will be addressed as such in future presentations of the DISN.
The packet data portion of DISN is to be comprised of three router networks. The three networks currently planned are NIPRNET, SIPRNET, and the TS/SCI JWICS.
Each of the DISN router networks is planned to provide a high-speed internetworking data transport service designed to support open systems and standards. The router network will provide long-haul routing of the standard DoD IP and the GOSIP. Although no other protocols are planed to be routed by the DISN router network, proprietary protocols can be converted or encapsulated into the DoD IP or GOSIP connectionless network protocol (CLNP) standard protocols prior to transmission.
DISN router networks will also support those users who are currently on the old style X.25 packet switching networks of the DDN (i.e., MILNET, DSNET-1, and DSNET-3) who are being migrated to a router-based network.
The DISN Router Network Subscriber Guide is for the technical staff within the DoD Services and Agencies who are supporting their S/As to subscribe and use the DISN router services. It provides a description of DISN router network subscriber services and subscriber connection requirements. Subscribers to the DISN router networks will use this document to determine how to interconnect to the network. In the interest of DISN performance and interoperability subscribers are strongly encouraged to transition to the DoD IP or GOSIP CLNP network services instead of continuing to use the X.25 protocol services.
Each DISN router network consists of a number of routers that are interconnected with one another with either Ethernet, for collocated routers, or high-speed serial links with line speeds varying from 64 Kilobits per second (Kbps) to T1 rate, which is 1.544 Megabits per second (Mbps). To the maximum extent possible, long-haul transmission circuits will transit the DISN Transmission Service, which is comprised of a smart multiplexer network. Those routers in each network that provide access points for subscriber connections are referred to as the Point of Presence (POP) routers.
DISN ROUTER NETWORK ARCHITECTURE
The services offered by each DISN router network are DoD IP service and GOSIP CLNP service. Subscriber systems can use each of the DISN router networks to carry other services, provided that they have been encapsulated or converted to IP or CLNP before being presented to a DISN POP router.
Three types of subscriber systems can be connected to each of the DISN router networks. These are networks with routers, networks without routers, and hosts (end systems).
This is the preferred option for subscriber connections to the network. The subscriber routing domain could contain multiple routers, networks, and connections. The subscriber router can be connected to a DISN POP router using any of the supported physical interfaces.
Wherever possible, subscribers are urged to connect through a router to the DISN POP router. If another organization on base already has router service, the subscriber is urged to negotiate with that organization to use a port from that router.
Subscriber networks without routers, in some cases, may be able to connect directly to a DISN POP router. DISN POP routers support Ethernet, Token Ring, and Fiber Digital Data Interface (FDDI) access.
Directly connected hosts are the least preferred option for connection to the router network. The subscriber host would connect to the DISN POP router with one of the supported serial interfaces and access the router using High-level Data Link Control (HDLC), Link Access Procedure-Balanced (LAPB), Point-to-Point Protocol (PPP), DDN-Standard X.25, or GOSIP X.25. The host must support either DoD IP or GOSIP CLNP.
As part of the Integrated Tactical Strategic Data Network (ITSDN), each DISN router network will have gateways for connectivity to the tactical environments. For general program information refer to the ITSDN Program Plan. For detailed implementation information refer to the ITSDN Ground Mobile Force Entry Point Implementation Plan, 15 April 1994.
The DISN strategy for network management uses a three tiered concept consisting of a Global Control Center, four Regional Control Centers, and many Local Control Centers.
The Global Control Center, located at DISA Headquarters, Arlington, Virginia, provides oversight function for management of all DISN services. The GCC serves as a focal point for the collection and exchange of regional DISN information. The GCC monitors DoD telecommunication networks, systems, and services on a worldwide basis. In some cases, the GCC also controls certain specified systems and telecommunications capabilities.
In addition to the DISN oversight role, the DISN configuration database will be managed by the GCC, with distributed database access and update capabilities available to the regional control centers and other DoD organizations. The Worldwide-On-Line System (WWOLS) is currently performing a similar function but primarily for point-to-point transmission circuits. A new database, the WWOLS Replacement (WWOLS-R) is currently in development.
There are four Regional Control Centers, two for the Western Hemisphere (WESTHEM) Region and one each for the Europe and Pacific Regions. Each of the RCCs has primary and backup responsibilities. Although the scope of their control is currently more limited, eventually both WESTHEM RCCs will be able to "see" the entire WESTHEM Region. Within limitations, the Europe and Pacific RCCs will be able to "see" beyond their regional boundaries. The four DISN Regional Control Centers are:
The regional control center at Fort Ritchie will perform oversight management of the system providing CONUS circuit-switched voice and data services. Fort Ritchie will also provide directory services for users of circuit-switched and dialup video services and manage the Secret level packet data network, SIPRNET.
The regional control center at Columbus will perfor transmission and bandwidth manager network oversight management. Columbus will also provide transmission help desk and trouble ticketing services. Columbus will also provide network information to Fort Ritchie and to the provider of video teleconferencing services. Columbus will provide oversight of video services and will work with the video services provider to meet video transmission requirements. Columbus will also manage the unclassified-but-sensitive (N level) packet data network, NIPRNET.
There is also a network management facility at Scott Air Force Base (AFB). Illinois, that is an adjunct facility to the Columus RCC. Currently, the Scott AFB facility is used to manage the Defense Red Switch Network (DRSN) and the DISN multiplexer network. Eventually, these management functions may be moved to the Columbus RCC.
Local telecommunication capabilities serving bases, posts, camps, and stations are usually managed by the Military Services and, in some cases, by other DoD agencies. Local network management is generally performed on site but may be consolidated at regional or global facilities that are established by the Services and agencies.
The DISN LES is the advanced worldwide telecommunications infrastructure approved by the Defense Advanced Research Projects Agency (DARPA), DISA, and the Assistant Secretary of Defense (ASD) (C3I) offering pilot services that provide access to next-generation capabilities.
The DISN LES is a high-bandwidth infrastructure that incorporates the ATM-based capabilities of bandwidth-on-demand with increased efficiency and bandwidth utilization to offer unclassified and classified ATM cell-bearing services. ATM service has been successfully extended to numerous CONUS locations via a T3 network and to the European Theater as part of support to JOINT Endeavor.
STRATEGIC OBJECTIVES AND IMPACT
MILSATCOM systems include those systems owned or leased and operated by the DoD and those commercial satellite communications (SATCOM) services used by the DoD. MILSATCOM systems consist of three primary segments: the earth terminal (ET) (AIRBORN, ground, sea) segment, space segment, and control segment. The key advantages of MILSATCOM systems are flexibility. Chairman, Joint Chiefs of Staff (CJCS) Memorandum of Policy (MOP) 37 establishes operational policy and procedures and provides guidance on MILSATCOM systems as directed by DoD Directive 5105.44.
MILSATCOM SYSTEMS
The DSCS is an integral component of the Global Defense Communication System. It is designed to provide vital Command, Control, Communications, and Intelligence (C3I) service to the United States and Allied Forces throughout the world by means of satellites. The DSCS, which consists of three segments (space, earth, and control), provides a reliable, high-capacity, quality communications capability in support of peacetime, contingency, and wartime operations.The DSCS Program Plan fiscal years (FY) 94-99 report is used by DISA and the Military Departments (MILDEP) for planning, programming, and budgeting of DSCS projects. The report compiles the Joint Chiefs of Staff (JCS) validated and projected communications requirements; identifies operational and logistical support responsibilities; relates time-phased research, development, test and evaluation program requirements; and identifies funding profiles for the MILDEPs. The DSCS TIP provides guidance to the MILDEPs and other Government agencies in implementing DSCS system elements.
There are currently two types of satellites in the DSCS constellation: DSCS II and DSCSIII.
DSCS II was the first fully operational DSCS space subsystem. Only one active DSCS II satellite remains in use and is located over the Indian Ocean region. The DSCS II provides four channels of communications in the X-Band of the SHF frequency range. Antenna coverage is accomplished using two earth coverage horns, one steerable area-coverage gimbaled dish, and one steerable narrow-coverage gimbaled dish antenna.
The DSCS III constellation consists of six satellites in geostationary orbit. Each satellite is a three-axis stabilized vehicle using the same SHF frequency band as the DSCS II. Six channels and six transponders (one channel per transponder) are provided for both protected and unprotected communications signals. Antenna coverage is provided through four earth coverage horns (two receive, two transmit), one gimbaled dish transmit antenna, two 19-element multi-beam transmit antennas, and one 61-element multi-beam receive antenna, which can be adjusted in both phase and amplitude.
The earth segment consists of Earth Terminal (ET), Digital Communications Satellite Subsystem (DCSS), Interconnect Facility (ICF), and Technical Control Facility (TCF).
The earth terminals consist of the antenna, transmitting, receiving, and signal processing equipment necessary to establish the uplinks and downlinks with a satellite.
The AN/FSC-78 and AN/FSC-79 Heavy Terminals (HTs) and AN/GSC-39(V)2 Medium Terminals (MTs) have operated as part of the DSCS satellite network since the mid-70s and have supassed their design life of 15 years. The modernization effort will provide for the upgrade of aging electronics in the HTs and MTs so that all DSCS SHF strategic earth terminals will use common electronics and logistics support. In encompasses the equipment from the antenna interface to the communications and control subsystem interfaces. The result will extend the life of the terminals for another 15 years, increase readiness, reduce training and logistics support, conserve energy and improve maintainability.
The State-of-the Art Medium Terminal (SAMT) is a high-capacity, medium sized, Super High Frequency SHF) Satellite Communications Terminal designed to operate in the DSCS satellite network. The terminals are operated by the various services under the operational control of DISA. This system is characterized by computer aided fault isolation, hierarchial control (remote console and external control possible) and automatic equipment switch-over to redundant equipment with High-Altitude-Electromagnetic Pulse (HEMP) protection in vans or fixed site buildings. SAMT includes a 38 foot OE-371/G antenna.
Jam Resistant Secure Communications (JRSC) is an add-on to the DSCS resulting from the Secretary of Defense requirement to improve Worldwide Military Communication Command and Control ystems (WWMCCS) capability of jam resistant secure communications via satellite. JRSC consists of SHF satellite terminals packaged to satisfy JRSC peculiar requirements.
The AN/TSC-85B and AN/TSB-93B are SHF systems that provide reliable multichannel capacity satellite communications with an anti-jam capability. Both terminals operate with an eight foot diameter antenna through the DSCS satellite network. AN/TSC-93B provides a capacity of 24 channels that can operate in a point-to-point mode or as a non-nodal terminal in a nodal network. AN/TSC-85B provides a capacity of 48 channels that can also operate in a point-to-point mode or as a nodal terminal in a nodal network. The Basebamd Improvement Modification (BIM) is a directed program change by Joint Chiefs of Staff (JCS) to the Army Ground Mobile Forces (GMF) SHF program. This change increases and improves satellite efficiency and interoperability between Army (AN/TSC-85B, ANTSC-93B) and Air Force (AN/TSC-100A, AN/TSC-94A) terminals. The terminals use spacecraft resources more efficiently while improving network management and control.
The AN/TSC-94A and AN/TSC-100A, Ground Mobile Forces (GMF) multichannel SHF Satellite Communications Terminals are shelter mounted. The terminals are full duplex trunking, and are utilized by the Air Force to provide subscriber voice channels or TRI-TAC groups. Both terminals provide a high order of component commonality, redundancy, and Built-In-Test-Equipment (BITE). In a stress environment, both have the capability to operate with anAnti-Jam Control Modem (AJCM). AN/TSC-94A is capable of operating simultaneously with up to four AN/TSC-100A nodal terminals in a mesh or hub spoke mode. Both terminals use an 8 foot antenna or a 20 foot Quick Reaction Satellite Antenna (QRSA). Both terminals interoperate with the GMF AN/TSC-85B and AN/TSC-93B terminals.
The AN/TSC-143, Prototype Tri-Band Tactical Terminal (PT3) is a Commercial Off the Shelf (COTS) Non-Development Item (NDI) multichannel satellite communications terminal mounted on a HHMMWV including the Antenna and primary/alternate power source. The system was designed with the capability to operate over commercial or military transponder based satellite systems in X (DSCS), C and Ku (commercial) SHF frequency bands utilizing one transmit carrier and three receive carriers. The PT3 has an integrated Switch Multiplex Unit (SMU) to provide local subscriber service to 35 users as well as terminate 5 Digital Trunk Groups (DTG) with expanded support for 165 additional users. The PT3 interoperates with the GMF MCIS (AN/TSC-85/93/94/100) to include interface with the Mobile Subscriber Equipment (MSE), TRI-TAC digital and analog networks with access into the Digital Subscriber Network (DSN).
Super High Frequency (SHF) Triband Advanced Range Extension Terminal (STAR-T) is a High Mobility Multi-purpose Wheeled Vehicle (HMMWV) mounted, multi-channel Tactical Satellite Terminal (TACSAT). It has a tri-band capacity in SHF and will operate over commercial and military SHF satellites. Selected terminals will also have an integrated switch that will interface with both commercial and joint military switching systems. The STAR-T has strong joint service applicability and potential for cooperative investment to replace current SHF multi-channel TACSAT terminals and some switching systems. The STAR-T program will incorporate Demand Assigned Multiple Access (DAMA) Control and Monitoring System (DACMS) features which will support Special Operations Forces and all other users.
The DCSS encompasses the modulation, multiplexing, coding, and processing equipment necessary for the transformation of various types of voice and user data into a digital form suitable for transmission over a satellite communications link. The DCSS is covered in detail in Technical Description, Digital Communications Satellite Subsystem (DCSS) by the United States Army Satellite Communication Agency, Fort Monmouth, NJ 07703, AMCPM-SC-5G.
For minimum mandatory requirements to ensure interoperability of PSK modems operating in Frequency Division Multiple Access mode, the following standard is mandated:
MIL-STD-188-165, Interoperability and Performance Standards for SHF Satellite Communications QPSK Modems (Frequency Division Multiple Access (FDMA) operations), January 13, 1995.
The AN/USC-2(V) system is an advanced spread spectrum satellite communications set that provides multiple access and anti-jam communications through satellite repeaters. The net provides an anti-jam network critical control circuit, multiple anti-jam digital data communications channels operating at any rate from 75 bps to 4.9152 Mbps with associated 75 bps order wires. It provides interoperability with the Navy OM-55/WSC satellite communications modem groups and is capable of operating in the TDMA mode. It provides precise time transfer between interoperating AN/USC-28(V) terminals. The AN/USC interfaces with terminals at a 70 MHz or 700 MHz intermediate frequency.
The UMS, which includes a family of modems and an Interim System Planning Computer (ISPC), will provide survivable, anti-jam (AJ), anti-scintillation (AS), low probability of exploitation (LPE), interoperable, SHF, command and control connectivity for military forces during all phases of conflict. The UMS will provide a means for strategic and tactical forces under the command of the United States, United Kingdom, France, or the North Atlantic Treaty Organization (NATO) to have interoperable voice and digital data satellite communications under worst case jamming and nuclear scintillation while using nonprocessing transponders of the DSCS II and III, NATO III and IV, SKYNET 4, and SYRACUSE satellite systems. The UMS is configured for installation at fixed sites and on land, sea, and airborne platforms/terminals.
The ICF provides the connectivity between the technical control facility (TCF) and the ET. Typically, the medium is baseband cable, optical fiber, or a line-of-sight (LOS) microwave link.
The TCF provides the interface between the satellite system and the users or other transmission services. The TCF also provides some technical control and management functions.
The DSCS Operations Centers (DSCSOCs), collocated with selected dual-antenna ETs, are typically the facilities used to monitor satellite communications and to control and maintain the satellite payload. The DSCSOC typically conducts the daily operations and control of the DSCS under the authority of the DISA Area Communications Operation Center (ACOC). The DSCSOC typically provides direct operational control of the DSCS ETs and the satellite payload by using the DSCS equipment to maintain the correct network parameters.
The joint military services program called MILSTAR was conceived to develop a survivable, worldwide satellite communications network for strategic and tactical users beginning in the 1990s and extending well into the 21st century. MILSTAR will support emergency action message (EAM) dissemination; the command, control, coordination, and status reporting requirements of the unified and specified commands; and tactical forces communications.
The terminal equipment uses various DoD SATCOM systems, including the Fleet Satellite/Air Force Satellite (FLTSAT/AFSAT), Navy UHF follow-on (UFO) satellite, and MILSTAR system. This equipment supports the Army operations concept by providing uninterrupted communications beyond the LOS capability for advancing tactical forces. The MILSTAR system consists of mobile tactical satellite communications terminals and fixed strategic terminals.
For waveform, signal processing, and protocol requirements for acquisition, access control, and communications for LDR (75-2400 bps) EHF satellite data links, the following standard is mandated:
For waveform, signal processing, and protocol requirements for acquisition, access control, and communications for MDR (4.8 Kbps - 1.544 Mbps) EHF satellite data links, the following standard is mandated:
For 5 Kilohertz (KHz) or 25 KHz single-channel access service supporting the transmission of either voice or data, the following standard is mandated:
For 5 KHz DAMA service, supporting the transmission of data at 75-2400 bits per second (bps) and digitized voice at 2400 bps, the following standard is mandated:
For 25 KHz TDMA/DAMA service, supporting the transmission of voice at 2400, 4800, or 16000 bps and data at rates of 75 bps - 16 Kbps, the following standard is mandated:
For data controllers used to operate over single access 5 KHz and 25 KHz UHF SATCOM channels, an interoperable robust link protocol that can transfer error-free data efficiently and effectively over channels that have high error rates is mandated:
The UHF/FO, or UFO, is a new family of UHF satellites intended for use with, or to replace, the current FLEETSAT and LEASAT constellations. In addition to supporting the military UHF mission, UFO will support the GBS on three of its satellites. Each of the supporting satellites will have four 24 Mbps transponders operating in the Ka band.
The architecture for future (2010-2025) space communications is comprised of military and commercial systems providing communications services to DoD users needing mobility, high capacity, protection (anti-jam) of service, and survivability (anti-scintillation) of service. The architecture must provide these services in an environment that accommodates advances in technology, variations in fiscal resources, and changes in national security policy.
The architecture address 4 space segments; three segments based on frequency range (EHF, SHF, and UHF), with the fourth segment being based on geographic service area (north of 65 degrees of northern latitude).
The EHF system will provide anti-jam and anti-scintillation communication services (unique to military requirements) to DoD that maintains freedom of action during deployment, maneuver, and engagement phases of military operations. The basic transition strategy is to continue the current MILSTAR system through DFS-6, but plan military operations relying on a less than fully populated MILSTAR constellation.
The initial improvement increment will be to increase the single channel protected data rate to 6-8 megabits per second (Mbps) using the existing MILSTAR medium data rate (MDR) waveform while maintaining backward compatibility with MILSTAR II. Later improvements will increase that rate to the 10s of Mbps range using a waveform compatible with other systems within the architecture (especially those operating in the Ka-band).
The architecture provides core DoD high capacity service, with assured control and access, using a military owned system operating in the Ka- and X-bands of the SHF frequency range. The architectural goal of the X/Ka system is to provide high capacity communication service to all eschelons required to support precise engagement. The transition strategy is to continue deployment of the existing DSCS satellites, incorporating the service life enhancement program (SLEP), and the GBS package on UFO. An interim "commercial like" X/Ka system will be deployed to replenish/augment DSCS. "Commercial like" implies that the system will be built using commercially available components and commercial practices. Initail implementation will likely be via "bent pipe" transponders with future migration to a satellite processed and switched capability following commercial development. A desired goal is for the future X/Ka system to be interoperable with other military space systems, including commonality of waveform with the EHF system as a minimum. Military operations should be planned for use of a less that fully capable DSCS constellation.
The architectural goal of the UHF system is to provide adequate communication service to enable dominant maneuver and information superiority. The strategy is to sustain current UHF capability, deploy currently planned UFO, and decide in the 2003 to 2005 timeframe on the preferred approach to provide netted mobile and hand-held voice, paging, and low-data-rate broadcast service. Three military approaches have been identified: a cellular system at medium earth orbit (MEO); a cellular system at geosynchronous orbit (GEO); and extending UHF capability indefinitely, but augment the wide-area mobile netted service of UHF SATCOM with non-space systems such as unmanned aerial vehicles (UAV). Military operations should be planned with a less than fully capable UHF constellation.
In order to fulfill the military need for protected communication service, especially low probability of intercept/detection (LPI/LPD), to units operating north of 65 degrees northern latitude, the space communications architecture includes this capability. An acceptable approach to achieving this goal is to fly a low capacity EHF system in a highly elliptical orbit (HEO), either as a hosted payload, or as a "free-flyer", to provide service during a transition period, nominally 1997-2010. A single, hosted EHF payload is already planned. Providing 24 hours per day service requires a two satellite constellation at HEO. Beyond 2010, the LOI/LPD polar service could continue to be provided by HEO EHF payload, or by the future UHF system - if that is in an orbit providing polar coverage/access, or a commercial system with polar coverage/access.
The strategy is to provide higher data rate, protected services on mobile platforms; move toward more multi-band terminals (especially among military X, Ka, and UHF frequencies) and make evry attempt to leverage commercial technology such as common printed circuit boards/components, processor controlled radios, and remotely reprogrammable systems. In addition, future terminal designs should target ease of operation and maintenance; reduce inventory of service unique, limited purpose terminals; and establish measurable goals to reduce operations and maintenance costs.
The strategy is to consider the network management and satellite control systems as the integrating component of the architectur, designing it from an architectural perspective rather that as a component unique to each system. Near term steps should be taken to integrate the DISN, SATCOM, and GBS nodes of the communications infrastructure. The design of the network management andsatellite control system must also support assessment of communication architecture, warfighting visions, and weapons system communication needs by providing the interfaces and structure to support rapid prototyping and advanced technology demonstrations. the network management and satellite control systems must be user-focused, designed to meet the needs of the warfighter who is engaged in a dynamic and threatening battle-space.
For further information visit the "Space Architect's" Web page.
DISA is continuing an ongoing plan to acquire Commercial Satellite Communications activities to support long-haul mission requirements not requiring use of Military satellites, with Pacific Network to be implemented first, followed by Europe.
GBS is designed to provide warfighters with a worldwide, seamless, high throughput broadcast information service to support today's and tomorrow's missions. GBS will use three UFO satellites and leased transponders from CSCI. Uplinks will be at 30.0 - 31.0 GHz. Downlinks will be at 20.2 - 21.2 GHz. This Joint DoD program will utilize existing/emerging Satellite technology to push forward data from CONUS and OCONUS to the on-site requirer of the information. It is projected to have the soldier in the foxhole request data (using a laptop computer) through an intermediate local router to an OCONUS Theater Injection Point (Data Base Repository that is kept updated from the CONUS) which then "pushes" the requested data to the requester.
GPS user equipment must employ Precise Position Service (PPS) user equipment incorporating both Selective Availability and Anti Spoofing features to support combat operations. The GPS guidelines are documented in ASD Command, Control, Communications, and Intelligence. For all systems requiring timing and/or synchronization the GPS is the preferred reference signal.
C3I Memorandum "Development, Procurement, and Employment of DoD Global Positioning System, User Equipment," dated 31 April 1992, must be followed. Specific standards are being researched at this time.
A DISN Component Program to continue modernization of world wide long-haul communication capability through a DISN-EUR procurement contract. The DEB should be in place to take advantage of the deregulation of communications in the European Community that will occur in 1998.
The European strategy will be characterized by replacement or upgrades of switching equipment to provide modern and maintainable multifunction switching capabilities as compared to the Pacific Long-Haul Project which is establishing long-haul capability.
The purpose of the EKIP is to provide for C4I enhancements and upgrades in the Korean DII. These enhancements will increase reliability, survivability, performance, and operational capabilities. EKIP is a diverse program consisting of implementations in microwave, satellite, switching, and network management. The scope of the EKIP implementations follow.
The Digital Microwave Upgrade (DMU) replaces the old AN/FRC-162 and AN/FCC-97 radio/mux systems with state of the art SONET radio/mux systems. This implementation consists of 15 sites divided into three phases. Only Phase I (Yongson, Osan, Madison, Humphreys) is fully funded.
The Korean Network Management System (KNMS) is a state of the art management system for the FOCSIK backbone. KNMS replaces the ACORN system. KNMS will be engineered, installed, and tested at 16 FOCSIK sites in Korea.
Tactical to Strategic (TACSTRAT) provides for the engineering, installation, and test of the GTE switched multiplex unit (SMU) and ancillary equipment at six locations in Korea. TACSTRAT will provide tactical interface for switched systems such as the AN/TCC-39D into the strategic DISN backbone.
The Defense Information Infrastructure Contingency Satellite Communications Terminal (DSAT) provides for increased survivability and alternate route capability for the FOCSIK. The scope of this effort encompasses the engineering, installation, and test of eight DSAT ICFs to support the contractor-provided DSAT terminals.
The existing digital wideband system interconnectivity that DoD and other government users utilize in the Washington, DC, area consists of microwave, satellite, and fiber optic systems, with corresponding TCFs at the Pentagon, Fort Meade, Fort Detrick, Fort Belvoir, and Site R.
The Japan Reconfiguration and Digitization-Phase II (Okinawa MW and FO system) and the Hawaii Information Transfer System (HITS) are to replace HAWS. They also provide for integration of state of the art technologies (e.g., SONET).
The project is to provide transmission systems and corresponding TCFs and PTFs in Panama.
The project is to provide transmission systems and corresponding TCFs and PTFs in Puerto Rico.
The project is to establish and upgrade the existent fiber, microwave, and TCF systems in Saudi Arabia.
The program provides for upgrade of the DISN Technical Control Facilities and Patch and Test Facilities (PTF) worldwide in support of the Commanders in Chief (CINC). Matrix switches, timing and synchronization equipment, order wire, tactical interface, LSTDM, and battery upgrades are some of the subprojects included in the program.
GCCS has been designated the single command and control system for DoD. GCCS improves the joint warfighter's ability to manage and execute crisis and contingency operations. It provides a means to interface with joint, service-specific, and Federal agency C4I systems for peacetime deliberate planning as well as crisis planning and execution. The GCCS uses the DISN for its worldwide transmission services.
The C4IFTW concept is committed to the challenge of meeting the warrior's quest for information needed to achieve victory for any mission, at any time, and at any place. GCSS is the final piece of the C4IFTW concept. It is a demand-driven, joint, warfighter-focused initiative to accelerate delivery of improved support capabilities. Using the same approach, methodology, practices, tools, and integration procedures as the GCCS, it is a strategy that integrates existing combat support systems to gain efficiency and interoperability in support of the warfighter. GCSS will provide the warfighter with a fused, real-time combat support view of the battlespace.
Besides GCCS and GCSS both the DISN and DMS are needed to complete C4IFTW. GCSS will rely on all components of the DISN for information transport services including voice, text, and imagery. DMS provides the infrastructure for secure, accountable, reliable writer-to-reader messaging for the warfighter at reduced costs.
The Joint Interoperability and Engineering Organization (JIEO) Center for System Engineering (CFSE) publishes Engineering Publications (EP) to provide engineering guidance to DoD Departments/Agencies. Engineering Publication No. 1-92, dated June 1992, provides performance requirements for use in commissioning DCS Transmission Subsystems. It is applicable to cable, microwave, and satellite transmission subsystems. In the past DISA has used a myriad of documents in the specification of performance for procurement and commissioning. To facilitate its use this publication contains an extensive bibliography of other documents used by both military and commercial organizations.
For HF Radio Communications the following standards are required.
DoDD 4630.5, DoDI 4630.8, and CJCSI 6212.01 outline the basic interoperability and standards conformance requirement. The Joint Interoperability Test Center (JITC) has been designated as the executive agency for certification of such requirements and makes available its test facilities for use by DoD and industry in certification testing. The requirement for HF radio, HF ALE, and HF data modem interoperability and standard compliance testing has been established in both the military and civil sectors of the federal Government. Based on the DoDD, DODI, CJCSI, and MIL-STDs, the JITC developed two JITC Instructions (JITCI), 380-195-01A and 380-195-01B, to test compliance to the MIL-STDs.
For both ALE and radio subsystem requirements operating in the HF bands, the following standard is mandated:
For anti-jamming capabilities for HF radio equipment, the following standard is mandated:
For HF data modem interfaces, the following standard is mandated:
For radio subsystem requirements operating in the VHF frequency bands, the following standard is mandated:
For long-haul user interface, various radio subsystems are available to connect into the long-haul trunk. Examples are ManPack LOS as operator input devices, Local Trunked Nets interconnected through a central hub with interconnectivity into the long-haul backbone, and connectivity through on-orbit transponders.
For radio subsystem requirements operating in the UHF frequency bands, the following standard is mandated:
For radio subsystem requirements operating in the SHF frequency bands, the following standard is mandated:
A detailed listing of Information Transfer Mandated Standards and Internet links to these standards are identified in Appendix B of the JTA. These standards are required for interoperability between and among systems, supporting access for data, facsimile, video, imagery, and multimedia systems. Also identified are the standards for internetworking between different subnetworks and transmission media standards for SONET and radio links. These standards promote seamless communications and information transfer interoperability for DoD systems.
SONET is a telecommunications transmission standard for use over fiber-optic cable. SONET is the North American subset of the ITU standardized interfaces, and includes a hierarchical multiple structure, optical parameters, and service mapping. The following standards are mandated:
ANSI T1.105, Telecommunications - Synchronous Optical Network (SONET) - Basic Description Including Multiplex Structure, Rates, and Formats (ATIS) (Revision and Consolidation of ANSI T1.105-1991 and ANSI T1.105A-1991) ANSI T1.107 Digital Hierarchy - Formats Specifications, 1995 ANSI T1.117, Digital Hierarchy - Optical Interface Specifications (SONET) (Single Mode - Short Reach), 1991.
Synchronous Digital Hierarchy (SDH) is the European flavor of SONET. The citation of applicable ANSI standards for SONET does not assure C4I interoperability in regions outside North America where standards for these services differ. The JTA recognizes that this is a critical area affecting interoperability but does not recommend specific solutions.
In addition to the above, most of the Telecommunications Management Network (TMN) standards are required to gain the full potential of SONET.
Wireless data networks provide users with the freedom to roam while allowing them to communicate to and from a portable computer or terminal. Several wireless data networks are available today:
Personal Communications Systems have evolved from the old Mobile Telephone Service (circa 1946). Advances in available technology have allowed additional services (e.g., data) to be added to the original voice communications capability. Advancing technology has also allowed significant increases in efficient use of the allocated sprectrum.
The original cellular service in the United States was an analog system using frequency modulation (FM) and frequency division multiple access (FDMA). This system, called Advanced Mobile Telephone Service (AMPS), is still in use. However, digital systems are displacing the analog systems.
Digital cellular systems in the United States fall into two categories: time division multiple access (TDMA) and code division multiple access (CDMA). Both categories use the IS-41 standard to access the public switched telephone netwoek (PSTN).
TDMA digital cellular systems use the IS-54 standard. Each frequency channel is divided into time slots within a data frame. Each channel slot comprises a single circuit path. The number of time slots within a frame determines the number of users who can use the channel at any given time. In the IS-54 system, TDMA is used in conjunction with FDMA. FDMA is necessary to divide the frequency allocation into a number of narrow-band channels.
The IS-95 standard is based on CDMA. CDMA is not capacity limited by the number of channels or the number of time slots as are the analog (FDMA) and TDMA systems. CDMA systems are capacity limited by the performance degradation caused by interference among users. There are, typically, two techniques used for CDMA: frequency hopping spread spectrum and direct sequence spread spectrum. Both techniques require a unique digital code (called a psuedorandom noise (PN) code) be assigned to each user. The PN code is used to spread the data elements over multiple frequencies for transmission and to reassemble the data elements from the frequency spread for reception.
In frequency hopping spread spectrum, a wide frequency band is divided into many narrow-band channels. the PN code is used to make the transmitter hop from one channel to another at a rapid rate in the psuedorandom sequence. For reception, the same PN code is used to rapidly tune the receiver in the same psuedorandom sequence.
There are two methods to generate direct sequence pread spectrum. One method modulates the carrier with the data stream, then modulates the resultant signal with the PN code sequence. The second method (the one most commonly used) modulates the PN code sequence with the data stream, then modulates the carrier with the resultant signal.
Cellular service in the United States has frequencies allocated in two different blocks for each defined service area. Service areas for licensing of cellular operations were defined by the FCC based on modifications of definitions by the Office of Management and Budget. These areas consist of 306 Metropolitan Statistical Areas (MSAs) and 482 Rural Service Areas (RSAs). There are some rural areas within some MSAs and some RSAs are more "rural" than others. Each of the two different frequency blocks has 416 channel pairs available (21 of these channel pairs are reserved as control channels) with a30 kHz spacing. Block A and B frequencies were reservec in the initial licensing by the FCC for non-wireline and wireline carriers, respectively. In addition, transmit frequencies for mobile-to-base station and for base station-to-mobile are separated by 45 MHz. The frequency allocations for cellular service in the United States are shown below.
Frequency Block Mobile-to-Base Station Base Station-to-Mobile
Block A 824.04 - 834.99 MHz 869.04 - 879.99 MHz 845.01 - 846.48 MHz 890.01 - 891.48 MHz
Block B 835.02 - 844.98 MHz 880.02 - 889.98 MHz 846.51 - 848.97 MHz 891.51 - 893.97 MHz
PCS comprises the services and technologies that are the second generation of digital mobile telephone service. These include both voice and data services coupled with the benefits of advanced network services. While PCS was originally envisioned as an advanced mobile telephone system based on a microsell architecture, market forces are driving it in the direction of a system similar to digital cellular but operating at higher frequencies. PCS does, however, offer paging and short messaging services among other services not found in digital cellular.
the spectrum allocated for PCS in the United States, shown below, is divided into six licensed blocks, and one unlicensed block. The unlicensed block is to be used for low power voice and data systems such as wireless private branch exchanges (PBXs). Blocks A and B are licensed within 51 service areas based on the Major Trading Areas (MTAs), and Blocks C, D, E, and F are licensed within 493 smaller service areas based on Basic Trading Areas (BTAs) set forth in the 1992 Rand McNally "Commercial Atlas and Marketing Guide". The PCS rules (FCC Docket 90-314) specify that Block A, B, and C "licensees must provide coverage to one third of their service area population within five years and to two thirds within ten years" and that Block D, E, and F "licensees must provide coverage to 25 percent of their service area population within five years or submit a showing of equivalent or substantial service". One intent of these "build-out" requirements is to ensure service to rural customers.
Frequency Allocations for PCS Service in the United States
Frequency Block Mobile-to-Base Station Base Station-to-Mobile
Block A 1850-1865 MHz 1930-1945 MHz Block B 1870-1885 MHz 1950-1965 MHz Block C 1895-1910 MHz 1975-1990 MHz Block D 1865-1870 MHz 1945-1950 MHz Block E 1885-1890 MHz 1965-1970 MHz Block F 1890-1895 MHz 1970-1975 MHz Unlicensed 1910-1930 MHz 2390-2400 MHz
Technical standards for the PCS air interface are being developed in the Joint Technical Committee on Wireless Access (JTC). The JTC is a joint activity between Committee T1 and the Telecommunications Industry Association (TIA). Within the JTC, there are six air interface technologies being standardized for the licensed PCS blocks. A seventh standard may be added which will be based on the Digital European Cordless Telephone (DECT) standard. Four standards are being developed for the unlicensed band, three are based on current digital cellular standards.
The licensed block PCS technologies can be divided into two types of systems based on intended coverage. One, called a high-tier system, is targeted for large cell applications much like existing cellular systems. The other, called a low-tier system, is targeted for microcell applications. The high-tier technologies tend to be robust against the impairment effects of radio transmission, such as multipath from reflections, scattering, and Doppler spreading created by motion of the mobile. However, high-tier technologies are commensurately more complex and provide lower quality voice and lower data rates. The low-tier technologies are more intolerant of multipath and are designed for operation at pedestrian speeds. However, low-tier technologies provide higher quality voice and higher data rates. Cell radii for the high-tier systems can range up to a few tens of miles, while cell radii for the low-tier systems range only up to a few hundred yards.
All proposed PCS technologies are digital. In digital transmission of voice, the original analog voice signal is converted to a sequence of binary numbers (bits), encoded with error detection and correction bits, modulated, possibly spread in frequency, and then transmitted. At the receiver, the signal is despread if necessary, demodulated, decoded, and then converted back into an analog signal.
PCS systems can provide data transmission services in addition to voice services. There are two primary ways to provide data transmission in a PCS system designed for voice transmission. In one case, the data stream bypasses the voice encoder and is injected directly into the digital system. This is the most appealing method since it provides the maximum data rate. The difficulty is that it requires specific modifications to the PCS system. There must be special equipment at both ends of the radio link to give access to the data stream, thereby adding to the cost of the service. The other approach is to use the more traditional voice-band modem and not bypass the voice encoder. A traditional voice-band modem modulates the audio frequency carrier with the data stream for transmission over a voice circuit. The frequency spectrum of the modem output falls within the required voice bandwidth.
In using the voice-band modem, the characteristics of the voice encoder are important. There are two basic methods of voice encoding used by PCS systems to convert the analog voice signal into a digital bit stream: waveform (or direct) encoding and predictive encoding. Waveform encoders tend to provide very high quality voice transmission, but require a higher bit rate. The higher bit rate reduces the spectrul effocoency of the system for voice circuits. Predictive encoders require a lower bit rate and are, therefore, more spectrally efficient, but provide poorer quality voice. Because of the higher data rate of the encoder, waveform encoders provide a greater voice bandwidth than do predictive encoders. Therefore, waveform encoders can support voice-band modem with higher data rates than predictive encoders. Data transmission, using a traditional voice-band modem, will result in a lower data rate than that achievable by bypassing the voice encoder.
The MSS is a "radiocommunications service between mobile earth stations and one or more space stations, or between space stations, or between mobile earth stations by means of one or more space stations". MSS services meet the needs of many industries worldwide. They are ideal for international applications where rapidly deployable mobile communications between countries are needed. Mobile satellite communications to and from ships and aircraft greatly aid their safe operation. The use of land mobile satellite terminals in times of emergencies to establish immediate communications is now being recognized as necessary.
The Federal Communication Commission (FCC) has licensed five systems for operation in the United States. Four of the licensed systems (Iridium, Globalstar, Odyssey, and AMSC) off voice and data capability at 1.6/2.4 GHz via large Low Earth Orbit (LEO) satellites. The other licensed system (Orbcomm) offers data onle service at 148/137 MHz via a small LEO satellite.
MSS voice and data implementations are expected to employ "dual use" handsets. That is the handset will be used for both cellular (or PCS) and satellite access. This is the approach used by AMSC. When the user handset is within range of the terestrial cellular access the user connects through the terrestrial system, but when outside of the provider's cellular range the handset accesses throught satellite connectivity. In Europe MSS is frequency termed "satellite-PCS".
MSS has the potential to expand PCS to a global system. Realization of the global PCS system will depend on establishing unternationally recognized standards, international agreements regarding use authorizations (completion of the ITU frequency coordination does not provide a guarantee that the satellite system will be authorized to provide space segment capacity for use in any particular country). Another constraint to competing global systems is frequency sharing and frequency reuse. Approximately 50 MSS systems have been proposed. It is not likely that the available frequency allocations will be able to support all of the proposed systems as global ones.
This project will provide state-of-the-art local communication nets that utilize finite individual frequency allocations without local interference between nets. Trunked Radio nets utilize a control station for the selection of repeaters to be used and the assignment of users to particular radio nets. The sharing concept recovers frequency allocations from multiple local nets, such as LMR and cellular, and provides a mission gain by allowing multiple nets to be combined if desired.
Cable systems utilizing copper or coaxial cable should be used only in circumstances where the local circumstances require them because of installation problems in modifying existent physical facilities.
Fiber optic cable (SONET standard) is the preferred long-haul terrestrial media for connecting end-user devices. Fiber optic cable provides high bandwidth (>100 Mbps) with high reliability and relatively high security.
FOCSIK provides for long wave, long-haul, fiber optic transmission system in Korea. It is projected to be accomplished in three phases, with a resultant communication reliability of 99.99 percent.
The FCC is an independent Government agency charged with regulating interstate and international communications by radio, television, wire, satellite, and cable. The FCC Office of Engineering and Technology web page provides the following information and references:
The federal Government provides voice, data, and video services over its FTS2000 system for federal users including DoD. DoD also uses this system for non-C3I requirements.
The FTS2000 program currently provides inter-city telecommunications services for 1.7 million federal Government users. The FTS2000 contracts were awarded by the General Services Administration (GSA) in 1988 and expire in December 1998. GSA and the Interagency Management Council (IMC) for FTS2000 have initiated efforts to define possible alternative concepts for Government telecommunications in the post-FTS2000 environment.
A Joint Concept Review Committee (JCRC) has been established to examine the feasibility of consolidating the post-FTS2000, DISN, and National Security/Emergency Preparedness (NS/EP) acquisitions.
The TRDSS is a NASA satellite constellation program consisting of a series of communication satellites in complementary orbits to provide continuous communication connectivity with the space shuttles from launch to touchdown. As a manned flight support system there is a robust margin of connectivity availability that can be contracted through NASA.
An overview of federal and non-federal spectrum use was developed by the National Telecommunications and Information Administration in July 1996. In order to serve its purpose as a quick reference, its length has been limited. Federal systems and missions that would have necessitated classification of the summary have been omitted although they represent significant federal requirements. Also, federal agencies lease many services from private sector providers and, as written, this summary indicates such uses only as non-Government use of the frequency spectrum. Therefore, it is not all-inclusive in its portrayal of U.S. spectrum requirements or its representation of the allocation table.
Individual long-haul communication services are tariffed and typically leased through DISA/DITCO St. Louis for both CONUS and OCONUS. Each service has a single office that requests this service from DISA. Some example providers of service are shown below.
There are a number of Government commercial contracts available for use, depending on requirements. Most requirements between posts, camps, and stations are accommodated through the DISN CONUS and OCONUS contracts.
Examples of CONUS long-haul carriers are AT&T, MCI, and Sprint.
As in the CONUS region a number of Government commercial contracts are available to provide service, with one major difference from CONUS Service. In OCONUS areas, there will normally be multiple providers for long-haul service, working within Government to Government agreements that may designate certain carriers. Examples of OCONUS prime/integrating contractors are ITT, AT&T, MCI, British Wire & Cable, INTELSAT, Sprint, and the national carriers in Italy and Japan.
ATM is a high-speed switching technology that takes advantage of low bit error rate (BER) transmission facilities to accommodate intelligent multiplexing of voice, data, video, imagery, and composite inputs over high-speed trunks. The network access protocols to connect user equipment to ATM switches are defined in the ATM Forum's User-Network Interface (UNI) Specification.
The protocol layers consist of an ATM Adaptation Layer (AAL), the ATM layer, and a physical layer. The role of AAL is to divide the variable-length data units into 48-octet units to pass to the ATM layer. AAL1 shall be used to support constant bit rate service, which is sensitive to cell delay but not cell loss. AAL5 shall be used to support variable bit rate service. The following standards are mandated:
At the beginning of FY 1997, DISA tuned up a Sprint ATM WAN to transport day-to-day traffic such as payroll and accounts receivable. Sprint's ATM service is becoming the new CONUS backbone for the DoD's NIPRNET.
Sprint's service was chosen due to its method of deploying SONET transmission routes at speeds that will reach OC-12, or 622 Mbps. Initially, the ATM net will connect 10 major NIPRNET nodes at speeds of DS-3 or 45 Mbps. DISA has acknowledged that, even though the ATM Forum has not completed the Multi-Protocol over ATM standard, it did not have the luxury of waiting until all standards were ready. The initial implementation uses the ATM Forum's LAN Emulation specification-LANE 1.0. In addition to the 10 NIPRNET nodes the fully meshed Sprint ATM backbone connects each site with Sprint's network access point for Internet traffic. To avoid local exchange bottlenecks Sprint worked with local exchange carriers (LEC) at each of the 11 nodes to provide DS-3 ATM access circuits rather than traditional DS-3 private lines to Sprint's ATM switches.
2.9.1.2 LES
The full capabilities of the DISN - LES infrastructure will be implemented in the future..
ISDN is a high-quality, switched digital communications product that gives a single phone line the ability to transmit voice, data, and packet data simultaneously at a relatively low cost. It is an international standard used to support integrated voice and data over standard twisted-pair wire and defines a Basic Rate Interface (BRI) and Primary Rate Interface (PRI) to provide digital access to ISDN networks. These interfaces support both circuit-switched and packet-switched services. ISDN is more prevalent in Europe and other parts of the world than in the U.S. There are engineering and technical considerations to investigate before the service is ordered worldwide.
The following standards are mandated:
Broadband ISDN (B-ISDN) is the master plan for an advanced digital telecommunications infrastructure that will provide high-capacity, high-performance voice, video, data, and integrated multimedia services to users on a world-wide basis. B-ISDN information transport is via ATM, a cell-based multiplexing technology that will give network providers unprecedented flexibility in allocating transmission capacity among increasingly diverse user needs. B-ISDN signaling will be accomplished using switchable B-ISDN channels and will offer users powerful new call-management capabilities.
ADSL solves the bottleneck over copper twisted-pair telephone lines that already exist. ADSL transmits megabits over twisted pair, enough to overrun the Internet. ADSL will start connecting real customers in 1997.
The ADSL Forum develops technical guidelines for architectures, interfaces, and protocols for telecommunications networks incorporating ADSL transceivers. The overall network diagram below describes the network elements incorporated in multimedia communications, shows the scope of the Forum's work, and suggests a group of transport configurations ADSL will encounter as networks migrate from Synchronous Transfer Mode (STM) to ATM.
| ADSL | Asymmetric Digital Subscriber Line |
| ATM | Asynchronous Transfer Mode |
| OS | Operations System |
| PDN | Premises Distribution Network |
| SM | Service Module |
| STM | Synchronous Transfer Mode |
| TE | Terminal Equipment |
| See System Reference Model for reference SM point definitions | |
Within the communications and computer networking field, separate bodies of standards have been developed and are in current use. Because of the significant number of standards used by the Federal Government including the DoD, it is recognized that there is a need for a common set of protocols to facilitate interoperability. The preferred body of standards are those based on the seven-layer reference model. This guide on long-haul transmission systems primarily deals with the physical layer (Layer 1) as well as some long-haul services up through Layer 4 (NIPRNET, SIPRNET, JWICS, etc.)
Synopsis of OSI Seven-Layer Reference Model
| Layer 7 | Applications: contains all of the information to be exchanged between different end systems; provides the means for end systems to agree to the semantics exchange. |
| Layer 6 | Presentation: arranges the presentation of the data so that the communications device (e.g., computer) can interpret it correctly. |
| Layer 5 | Session: furnishes the means to mark significant portions of the exchanged information; includes, for example, pages, chapters, and units of work. |
| Layer 4 | Transport: manages the transmitted data from end system to end system; establishes and manages network connections; responsible for assuring correct arrival of the transmitted information. |
| Layer 3 | Network: determines routing of the data packets; provides various procedures and functions in connection with the data transfer. |
| Layer 2 | Data Link: divides a data stream into frames for transmission; performs error detection and correction functions. |
| Layer 1 | Physical: handles transmission of the data stream in digital format across a communications channel. |
A partitioned portion of a complete data communications network is referred to as a subnetwork. Standards for local area networks (LAN) and other data communications services that are concerned with the physical and data link layers (layers 1 and 2) of the OSI Reference Model are referred to as subnetwork technologies. These technologies exhibit physical, functional, performance, and cost differences that render some subnetwork profiles more appropriate than others for particular systems. Generally, any subnetwork will support any of the transport and network layer standards.
The following table lists the most important subnetwork technologies and shows related existing and emerging standards.
Subnetwork Technologies
| Subnetwork Technology | Existing Standards | Emerging Standards |
| Local Area Network (LAN) | MIL-STD-187-700 (Interoperability and Performance
Standards for the Defense Information System)
Mil-STD-2045-14502 Part 4 (Internet Transport Profile: LAN Media Independent Requirements) Mil-STD-2045-1502 Part 5 (Internet Transport Profile: CSMA/CD LAN Media Dependent Requirements) |
MIL-STD-2045-14500 Part 4 (Transport Profile:
LANs, Using Token Bus)
MIL-STD-2045-145000 Part 5 (Transport Profile: LANs, Using Token Ring) |
| Fiber Optic | MIL-STD-187-700 | FIPS 146-2 (JAN 95)
FDDI DIS 9314-5 (FDDI-II) FDDI CD 9314-6 FFOL (FDDI follow-on LAN) |
| Frame Relay | MIL-STD-187-700 | None |
| Packet Switching | MIL-STD-187-700
MIL-STD-2045-14502 Part 3 (Internet Transport Profile: Wide Area Network Access) |
None |
| Synchronous Optical Network (SONET) | MIL-STD-187-700 | None |
| Asynchronous Transfer Mode (ATM) | MIL-STD-187-700 | None |
| Distributed-Queue, Dual-Bus (DQDB) | MIL-STD-187-700 | None |
| Switched Multimegabit Data Service (SMDS) | None | SMDS Interface Protocol (SIP) |
| Integrated Services Digital Network (ISDN) | MIL-STD-187-700 | MIL-STD-2045-14500 Part 6 (Transport Profile: ISDN) |
| Point-to-Point Subnetwork | FIPS 146-1{LAPB}
MIL-STD-2045-14502 Part 2 (Internet Transport Profile: Point-to-Point Links) |
MIL-STD-2045-13500 (Internet Relay Profile: Point-to-Point Protocol) |
15 April 1997
