international initiative that supports the development of standards and guidelines enabling transmission of digital television signals via wireline and wireless cable networks, satellite systems, and microwave configurations. DVB also describes procedures for accessing interactive broadband services and delivery of MPEG-2 compliant broadcasts. DVB standards also clarify the role of Cable Modem Distri- bution Systems (CMTSs) in supporting distribution of television programming and multimedia signals. Cable companies in the European Union, South America, Aus- tralia, and Asia endorse DVB specifications. 7.11.8.1 DVB-C (Digital Video Broadcasting-Cable Only) DVB-C (DVB-Cable Only) clarifies procedures for transporting audio, video, and data services over wireline cable networks and wireless cable networks based on the Local Multipoint Distribution System (LMDS) and the Multichannel Multipoint Distribution System (MMDS). Moreover, DVB-C specifications define channel cod- ing, packet formats, and cable network operations and support EuroBox and Euro- Modem interoperability. 7.11.8.2 DVB-S (Digital Video Broadcasting-Satellite) and DVB-T (Digital Video Broadcasting-Terrestrial) In addition to DVB-C, the DVB initiative defines common interfaces and interna- tional specifications for satellite (DVB-S) and terrestrial (DVB-T) services. DVB-S describes channel coding, frame format, and modulation functions for tele-applica- tions provided by satellites that operate in the 11 GHz and 12 GHz spectral bands. DVB-T indicates approaches for enabling digital terrestrial broadcasts. 7.11.8.3 DVB-CI (Digital Video Broadcasting-Common Interface) Based on specifications that include DVB-T (DVB-Terrestrial) and DVB-S (DVB- Satellite), DVB-CI (DVB-Common Interface) describes interfaces for CATV (Cable Television) and SMATV (Satellite Master Antenna Television) headend equipment and approaches for enabling SMATV installations in apartment complexes and local neighborhoods. 7.11.8.4 DVB-D (Digital Video Broadcasting-Data) DVB-D (DVB-Data) facilitates utilization of interoperable MVDSs (Multipoint Video Distribution Systems) for enabling data broadcasts. 7.11.8.5 DVB-RCC (Return Channel for Cable Service) The DVB-RCC (Return Channel for Cable Service) presents a framework for enabling bi-directional communications via cable networks in a specification endorsed by the ITU-T as Annex A to the ITU-T J.112 Recommendation. This Annex presents guidelines for establishing MAC (Medium Access Control) and Physical Layer interfaces, QoS guarantees, and cable network security. 0889Ch07Frame Page 307 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC 7.11.9 DVB MULTIMEDIA HOME PLATFORM (MHP) GROUP To enable interoperability of computer, broadcasting, and consumer electronics devices such as the EuroModem, the EuroBox, television sets, PCs, and laptops in the home environment, the DVB (Digital Video Broadcast) Multimedia Home Plat- form Group developed the Multimedia Home Platform (MHP). This standard facil- itates implementation of interactive digital television services and DVB-MHP-com- pliant digital STBs (Set-Top Boxes). 7.11.10 EUROCABLELABS AND CABLELABS: PARALLELS AND CONTRASTS CableLabs and EuroCableLabs sponsor research initiatives to determine the effec- tiveness of IP-over-cable solutions in delivering voice, video, and data transmission in real-time and evaluate capabilities of wireline and wireless cable deployments. Both groups endorse utilization of the HFC infrastructure for supporting interactive broadband services, support MPEG-2 compliance, and implement the QAM (Quadrature Amplitude Modulation) and the QPSK (Quadrature Phase Shift Key) protocols to facilitate reliable cable network transmission. Historical differences in analog television standards adopted by the Europe Union and the United States contributed to the development of DOCSIS (Data Over Cable Service Interface Specification) and EuroDOCSIS specifications. These dif- ferences also are reflected in the U.S. cable modem and the EuroModem, and in the U.S. STB and the EuroBox in the European Union. Cable products in development are designed to be compatible with ATM and IP technologies, thereby enabling Quality of Service (QoS) guarantees for rapid transfer of broadband services and time-sensitive material. In the United States, cable products are compliant with 10BASE-T Ethernet specifications. In addition, the advantages and limitations of using an ATM platform with a wireline cable network solution are under consider- ation by CableLabs. The viability of a hybrid fiber radio (HFR) deployment as a last-mile enabler for cable network service is also explored. A universal standard for cable network deployment over the last mile or local loop based on a consolidated CableLabs and EuroCableLabs solution is expected in the long term. 7.12 STANDARDS ORGANIZATIONS AND ACTIVITIES 7.12.1 C ABLE BROADBAND FORUM The Cable Broadband Forum is a nonprofit alliance that promotes utilization of cable broadband networks and services for enabling high-speed access to the Internet, telecommuting, videoconferencing, and IP telephony. The Cable Broadband Forum also endorses the efforts of CableLabs, the National Cable Television Association (NCTA), the Society of Cable Telecommunications Engineers (SCTE), and the Internet Engineering Task Force (IETF). Cable Broadband Forum participants include AT&T MediaOne, Microsoft, Cisco Systems, Intel, and AOL Time Warner. 0889Ch07Frame Page 308 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC 7.12.2 EUROPEAN TELECOMMUNICATIONS STANDARDS INSTITUTE (ETSI) H OME NETWORKS SPECIFICATIONS The European Telecommunications Standards Institute adopted the TS 101.224 HAN (Home Area Network) specification for supporting Multimedia Home Platform (MHP) operations based on the work of the Multimedia Home Platform Group. In addition, this specification clarifies approaches for establishing connections between HANs (Home Area Networks). HANs that are MPEG-2-compliant transport video, data, and audio; support IP-over-ATM services; and interwork with cable networks and DSL (Digital Subscriber Line) implementations. 7.12.2.1 ETSI HLN (Home Local Network) In addition, the ETSI HAN specification establishes a framework for a scalable and extendible home local network (HLN) based on the IEEE 1394 standard. An HLN links information appliances within rooms and between rooms in clusters of sub- networks and interconnects these clusters of subnetworks into an integrated home area network (HAN). ATM technology supports HLN connections to external net- works such as the Internet via the local loop. Transmission rates at 25 and at 51.84 Mbps, depending on user requirements, are supported. 7.12.3 INTERNATIONAL TELECOMMUNICATIONS UNION-TELECOMMUNICATIONS S TANDARDS SECTOR (ITU-T) In the cable arena, the International Telecommunications Union-Telecommunication Standards Sector (ITU-T) develops specifications for transmission of television signals via analog and digital circuits, interoperable digital television applications, and the telephone-interface for upstream transmissions. The ITU-T Study Groups define techniques for utilization of electronic program guides, evaluate capabilities of MPEG-2 (Moving Picture Experts Group-2) toolkits for webcasting, and develop technical solutions such as cable networks and DSL to safeguard transmissions distributed to the home over the local loop. In addition, the ITU-T Study Groups define specifications for eliminating transmission disruptions resulting from delay, noise, jitter, echo, and packet loss, and establish guidelines for supporting IP tele- phony service. Moreover, the ITU-T Study Groups develop Recommendations for interoperable set-top boxes (STBs) and clarify approaches for implementation of cable network applications such as video banking. 7.12.3.1 ITU-T Video Quality Experts Working Group The ITU-T Video Quality Experts Working Group develops algorithms that represent QoS (Quality of Service) guarantees for cable network applications and defines capabilities of asymmetric cable networks that support on-demand distribution of cable television programming. 0889Ch07Frame Page 309 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC 7.12.3.2 ITU-T Study Group 9 The ITU-T Study Group 9 develops cable television specifications for endorsement by the ITU-T. As an example, this Study Group defined the home digital networking interface for the ITU-T J.117 Recommendation that was approved in 1999. 7.12.3.3 ITU-T H.323 Recommendation Approved by the ITU-T in 1996, the ITU-T H.323 Recommendation supports video, audio, and data transmission across IP networks; streaming audio and video services; multimedia applications; and bandwidth-on-demand. In addition, this specification defines requirements for video and audio communications in LANs (Local Area Networks) that do not provision QoS (Quality of Service) guarantees and clarifies procedures for implementing the Real-Time Protocol (RTP), the Real-Time Control Protocol (RTCP), and the Resource Reservation Protocol (RSVP). The ITU-T H.323 Recommendation is not linked to a specific network infra- structure or hardware product. As an example, cable television set-top boxes (STBs), IP telephone handsets, and PCs (Personal Computers) feature ITU-T 323-compliant platforms and cable modem, DSL, and Frame Relay networks support ITU-T H.323-compliant services such as video-over-IP and voice-over-IP (VoIP). The ITU-H.323 Recommendation facilitates the use of VoIP technologies, appli- cations and services defined by the Voice-over-IP (VoIP) Forum. Also called IP telephony, VoIP technologies enable real-time analog voice transmissions via IP networks. The transmission process begins with the use of compression algorithms for creating small digital data streams at the point of call initiation. These streams are then formatted and compressed into digital data packets for network transmission. At the destination address, decompression algorithms reverse the process and decom- press the packets into data streams that are converted back to analog voice signals at the destination address. Approved in 1998, the ITU-T H.323v2 (ITU-T H.323, Version 2) Recommendation is an extension to the ITU-T H.323 Recommendation. 7.12.3.4 ITU-T J.83 Recommendation The ITU-T J.83 Recommendation defines channel coding, framing structure, and digital signal modulation for television signals distributed by cable networks. In addition, this Recommendation clarifies functions of MPEG-2 (Moving Picture Experts Group-2) transmission, forward error correction mechanisms, and QAM (Quadrature Amplitude Modulation) services. 7.12.3.5 ITU-T J.117 Recommendation Based on the IEEE 1394 standard, the ITU-T J.117 Recommendation establishes a framework for a home network that interlinks a maximum of 63 devices such as VCRs (videocassette recorders), television sets, set-top boxes (STBs), and PCs (Personal Computers) via a four- or a six-wire connection. 0889Ch07Frame Page 310 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC 7.12.3.6 ITU-T G.902 Recommendation The ITU-T G.92 Recommendation describes generic guidelines that support network management operations and maintenance services for broadband residential access networks such as cable modem configurations. 7.12.4 I NTERNET E NGINEERING T ASK F ORCE (IETF) An international standards organization, the IETF (Internet Engineering Task Force) supports implementation of open Internet standards to enable development of a global information infrastructure. IETF participants include vendors, researchers, operators, and network designers. 7.12.4.1 IETF IPCDN (IP-over-Cable Data Network) Working Group The IETF IP-over-Cable Data Network (IPCDN) Working Group develops standards for implementation of IP-over-cable networks. This Working Group also standardizes SNMP (Simple Network Management Protocol) MIBs (Management Information Bases) to support cable network administration and management services and pro- vision IP multicasts with QoS assurances. Moreover, the IP-over-Cable Data Net- work Working Group fosters implementation of standards-compliant cable network equipment, a telephone-return interface for upstream transmissions, and symmetric and asymmetric cable network operations. 7.12.4.2 IETF Uniform Resource Locator (URL) Registration Working Group The IETF URL (Uniform Resource Locator) Registration Working Group defines approaches for defining URLs in a television context and steps for URL registration. URLs (Uniform Resource Locators) enable the recording and playback of television programs and refer to audio, video, and data streams as applications or events. 7.12.5 M OVING P ICTURE E XPERTS G ROUP (MPEG) Established in 1988 as a joint International Stands Organization and International Electrotechnical Commission (ISO/IEC) Working Group, MPEG (Moving Picture Experts Group) describes a suite of technical specifications that govern video and audio compression. MPEG specifications also define video and audio coding formats for enabling representation of video and audio sequences in the form of compact coded data. Selected MPEG specifications are highlighted in the subsections that follow. 7.12.5.1 Selected MPEG Specifications 7.12.5.1.1 MPEG-1 and MPEG-2 The MPEG-1 specification describes syntax, compression, and synchronization func- tions for coded representation of audio and video packets that apply to video-coded 0889Ch07Frame Page 311 Monday, April 22, 2002 11:11 AM © 2002 by CRC Press LLC compact discs and CD-ROM (Compact Disc-Read Only Memory) formats featuring progressive video sequences that are not interlaced. The MPEG-2 specification describes syntax, compression, and synchronization functions and the use of time- stamps for coded representation of voice, video, and data streams. Designed for interlaced or progressive video sequences, MPEG-2 establishes Quality of Service (QoS) requirements for enabling sequenced data, audio, and video delivery. MPEG- 2 specifications apply to television programming, moving pictures, radio broadcasts, and DVDs (Digital Versatile Discs). 7.12.5.1.2 MPEG-4, MPEG-7, and MPEG-21 MPEG-4 serves as the de facto standard for delivering Web-based multimedia con- tent. MPEG-7 defines the Multimedia Content Description Interface (MCDI). MPEG-21 promotes utilization of advanced multimedia resources across heteroge- neous network environments and establishes a multimedia framework for enabling dependable access to and interactivity with multimedia objects. MPEG-21 also clarifies approaches for content creation, distribution, and production and procedures for intellectual property management. 7.12.6 NATIONAL CABLE TELEVISION ASSOCIATION (NCTA) The National Cable Television Association (NCTA) monitors cable network devel- opments and infrastructure improvements. This organization has joined with the broadcast industry to implement the TV Parental Guidelines rating system. The American Academy of Pediatrics, the National Association of Elementary School Principals, the National Education Association, the American Medical Association, and the National PTA (Parents Teachers Association) also endorse this rating system. 7.12.6.1 Cable in the Classroom Initiative Sponsored by the National Cable Telecommunications Association (NCTA), the Cable in the Classroom initiative fosters distribution of high-quality, commercial- free educational programming and online resources to approximately 81,000 schools. In addition, the Cable in the Classroom High-Speed Education Connection program provides free broadband access to the Web for teachers and students in K–12 schools and libraries where cable modem service is available. 7.12.7 WIRELESS COMMUNICATIONS ASSOCIATION (WCA) Originally known as the Wireless Cable Association International (WCAI), the Wireless Communications Association (WCA) supports innovations in the imple- mentation and delivery of broadband video and bi-directional voice and data services. LMDS (Local Multipoint Distribution System) and MMDS (Multichannel Multi- point Distribution System) operators in France, Australia, Mexico, Russia, and Brazil participate in this association. 0889Ch07Frame Page 312 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC 7.12.8 WORLDWIDE WEB CONSORTIUM (W3C) The Worldwide Web Consortium (W3C) designs Web specifications such as the Broadcast Markup Language (BML) for describing television content on the Web. The W3C Television and Web Interest Group coordinates BML initiatives with the Advanced Television Systems Committee (ATSC), the Association of Radio Indus- tries and Businesses (ARIB), the IETF URL (Uniform Resource Locator) Registra- tion Working Group, the Advanced Television Enhancement Forum (ATEF), and the European Broadcast Union (EBU). Approaches for standardizing cable modem equipment, determining the number of users that can be effectively supported by a neighborhood cable network segment, and forecasting the point at which Quality of Service (QoS) is negatively affected in cable networks are under consideration. Metrics for evaluating audio, video, and data throughput and network response time and procedures for reducing packet loss, latency, and jitter on cable networks are in development as well. 7.13 CABLE NETWORK MARKETPLACE Vendors supporting DOCSIS 1.0 and DOCSIS 1.1 standards-compliant cable modems include 3Com, General Instrument, Hewlett-Packard, Hughes, Intel, IBM, Bay Networks, AT&T MediaOne, Adelphia, Cabletron Systems, and Motorola. In addition, DOCSIS-compliant cable modems are also available from Newbridge Networks, Cisco, NextLevel Systems, Samsung, Toshiba, Nortel Networks, and Thomson Consumer Electronics. Terayon tests cable modem initiatives in Japan and Belgium. Com21 participates in cable modem field trials in Switzerland. Cable network configurations enable Web browsing, utility monitoring, E-commerce transactions, interactive tele-education programs, telephone services, video-on-demand (VOD), and cablecasts. (See Figure 7.4.) 7.13.1 ATHOME (@HOME) NETWORK AtHome Network (@Home Network) is a cable Network Service Provider (NSP) currently owned by cable operators including Comcast Corporation, Rogers Cable- systems, AT&T, and Shaw Communications. Based in Redwood City, California, AtHome Network delivers services to approximately 5 million broadband subscrib- ers via a DWDM (Dense Wavelength Division Multiplexing) network that supports transmission rates at 2.488 Gbps (OC-48) in an area of coverage that extends to 15,000 miles. AtHome Network partners with Real Networks in producing high- quality voice, video, data, and imaging applications, and with Segasoft and Liquid Audio in developing Web multimedia content. 7.13.2 AT&T MEDIAONE AT&T MediaOne brings high-speed Internet connectivity to all schools in its service areas and provisions access to Cable in the Classroom. AT&T MediaOne also 0889Ch07Frame Page 313 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC FIGURE 7.4 Configuration that supports IP overlays and works in conjunction with SONET, ATM, and WDM technologies. IP Over SONET, ATM or WDM at 622 Mbps Remote Content Server IP Switch/Router 622 Mbps OC-12 Fiber PSTN Internet Operations Support System IP Backbone Network IP Telephony Gateway Sniffer Server monitoring/analysis Network Management Local Application/ Content Servers Dist. Hub Dist. Hub Dist. Hub 2.4 Gbps OC-48 0889Ch07Frame Page 314 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC © 2002 by CRC Press LLC provides basic cable service; commercial-free academic programming and instruc- tional support materials, and works in concert with A&E, Discovery, Weather, and ESPN Networks in developing course content and Web resources. The AT&T Media- One COOL classroom initiative informs teachers and students about Web-based educational applications and cable television family viewing programs. In addition, AT&T MediaOne provisions links to the Real Education initiative for enabling access to undergraduate courses and certificate programs on the Web. Supporters of the Real Education program include the Universities of Pennsylvania, Colorado, and Drexel, and San Francisco, Eastern Michigan, and Connecticut State Universities. 7.13.3 TELEWEST COMMUNICATIONS, CABLE & WIRELESS COMMUNICATIONS, AND NTL In the United Kingdom, Telewest Communications, Cable & Wireless Communica- tions, and NTL provision wireline cable services via an HFC infrastructure. These services support access to a television mall that features entertainment, music, news, home shopping, television programs, interactive games, video-on-demand (VOD), travel assistance, educational applications, and E-commerce services. British Air- ways, Littlewoods Home Shopping Group, and Barclays Bank provision content for this mall. MPEG-2 video compression enables cinema-quality viewing. 7.14 WIRELINE CABLE COMPETITOR SOLUTIONS Wireline cable systems compete with technologies such as satellite, ISDN, and ADSL (Asynchronous Digital Subscriber Line) networks in supporting access to broadband networks from SOHO venues. As noted in Chapter 6, ADSL is a high- speed broadband residential access technology that supports information transport via the wireline infrastructure already in place for the Public Switched Telephone Network (PSTN). ADSL implementation involves the use of filters to split the existing phone lines into three frequency channels. These channels or circuits support traditional telephone service and enable upstream and downstream transmissions as long as the subscriber is no more than 18,000 feet from the local telephone exchange. If the distance from the local telephone exchange exceeds 18,000 feet, transmission rates decline. An ADSL modem failure only affects the virtual connection over the local loop between the customer premise and the local cable facility. With cable network implementation, the first user on a neighborhood cable network segment generally receives excellent service. However, each additional subscriber adds traffic to the network segment. If subscribers overload the neigh- borhood cable network segment with traffic, network services are adversely affected, resulting in transmission slowdowns, bottlenecks, and a noticeable decrease in sys- tem reliability and dependability. Because a subscriber shares upstream and down- stream cable network channels with other users, a cable system outage at one subscriber premise can cause cable outages at every subscriber household on the same neighborhood cable network segment. Inasmuch as cable channels are shared, 0889Ch07Frame Page 315 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC security problems occur with greater frequency on cable networks than with ADSL installations. 7.15 WIRELINE CABLE NETWORK IMPLEMENTATION CONSIDERATIONS Wireline cable configurations enable robust Internet, intranet, and extranet connec- tivity and real-time access to broadband services. Although early cable adopters seem satisfied particularly with downstream data transport, individuals evaluating cable systems for institutional implementations must be cautious. Cable configura- tions that enable multimedia deployment were deployed in the late 1990s. Standards are not yet fully developed or universally accepted for interconnecting cable equip- ment from different suppliers. As a consequence, distributed cable network equip- ment may not be interoperable. Information transmission from one cable operator’s system to another may not be feasible. Suitable options for facilitating reliable and dependable voice, video, and data transport via cable networks are in development. Because a cable network employs a shared communications platform, informa- tion transmissions are subject to degradation as more users are added to the network segment. Cable network operations can also be compromised by outages due to natural disasters such as earthquakes, snowstorms, and hurricanes, and computer and communications problems on the neighborhood cable network segment. Despite the expanded network bandwidth and capacity associated with HFC installations, technical problems in supporting end-to-end connectivity and ensuring the availability of return channel bandwidth for upstream transport can compromise network performance. Impulse noise, inadvertent fiber cuts, and the condition of the in-place HFC plant can also contribute to signal corruption, attenuation, and degra- dation. To facilitate troublefree transmission in noisy environments, cable NSPs and MSOs (MultiService Operators) use digital compression technology to increase transmission efficiency and improve network response time. Wireline cable networks are major contenders for bringing broadband access to diverse populations of users such as homebound learners and telecommuters in residential environments. Currently, 10BASE-T Ethernet is the most popular cable modem interface specification for cable modem installations at SOHO venues in the United States. As a consequence, the speed of the cable connection is automatically limited to 10 Mbps despite the capabilities of cable networks in supporting trans- missions at substantially faster rates. Cable service is not universally available. Cable modem subscribers are limited to using cable operators that provision cable service in their neighborhoods and purchasing cable modems that are compliant with the in-place cable configurations. These cable modems may not be compliant with DOCSIS specifications. To counteract cyberinvasions, the DOCSIS and the EuroDOCSIS specifications define baseline privacy specifications to sustain information integrity and data privacy across the shared cable medium. Nonetheless, cable networks are still susceptible to cyberinvasions by cyberhackers who can gain access to network files and directories maintained by all users sharing the same neighborhood cable network segment. 0889Ch07Frame Page 316 Wednesday, April 17, 2002 3:01 PM © 2002 by CRC Press LLC [...]... for evaluating cable network capabilities in enabling network interconnections, interoperable services, and broadband voice, video, and data delivery must also be conducted 7. 16 7. 16. 1 WIRELESS CABLE NETWORKS FEATURES AND FUNCTIONS Advances in technology and demand for fast access to broadband networks drive development of wireless cable networking solutions Wireless cable service eliminates the need... employ channels that are 6 MHz wide and support licensed and licensed-exempt operations in the ultra-high frequency (UHF) spectrum MMDS licenses are available at FCC auctions for every Basic Trading Area (BTA) in the United States 7.20.2 MMDS OPERATIONS MMDS implementations that operate in licensed spectrum between the 2.5 96 and 2 .64 4 GHz frequencies and between the 2 .68 6 and 2 .68 9 GHz frequencies are... INTEGRATED BROADBAND COMMUNICATIONS ON BROADCAST NETWORKS (IBCOBN) The IBCoBN initiative demonstrated the feasibility of using broadband cable networks for enabling video telephony and videoconferencing applications and dependable © 2002 by CRC Press LLC 0889Ch07Frame Page 3 36 Wednesday, April 17, 2002 3:01 PM access to Web resources In addition, this project validated capabilities of residential cable networks. .. 9 explores WPAN (Wireless Personal Area Networks, WHNs (Wireless Home Networks) , WLAN (Wireless Local Area Networks) , WMAN (Wireless Metropolitan Area Networks) , and WWAN (Wireless Wide Area Networks) technologies, protocols, architectures, and implementations for enabling access to wireline and/or wireless resources Chapter 10 examines satellite technologies, networks, applications, services, and solutions... metropolitan area Nucentrix Broadband Networks conducts MMDS field trials in Austin, Texas Cisco Systems supports licensed MMDS deployments with V-OFDM modulation in spectrum between the 2.5 96 and 2 .64 4 GHz frequencies and license-exempt MMDS implementations in the 5.7 GHz Unlicensed-National Information Infrastructure (U-NNI) frequencies MMDS solutions based on the use of cable modems with 64 QAM technology... designated community college locations 7. 26. 1.3 Province Learning Network (PLnet) British Columbia uses Delta Cable and Coast Cable Communications for provisioning access to the PLnet (Province Learning Network) initiative PLnet supports broadband connections to cultural, scientific, and educational programs and organizations throughout the province 7. 26. 2 7. 26. 2.1 GERMANY University of Hanover At the... high-speed access to the Internet Wireless cable networks complement services supported by wireline cable implementations As an example, wireless cable systems support interconnectivity to HFC backbone networks for transporting multimedia signals over the local loop, enabling interactive television programming, and supporting IP telephony 7. 16. 2 INSTALLATIONS In broadband fixed wireless cable network transmissions,... connectivity to backbone networks that provision access to broadband applications and Web resources at fast rates Barriers and constraints associated with the existing PSTN infrastructure in accommodating user demand for access to bandwidth-intensive distance learning and teletraining applications over the first mile contribute to accelerating deployment of wireline and wireless broadband cable networks In addition... negatively affected Nonetheless, cable networks affordably facilitate links to broadband applications and remain viable solutions for overcoming local loop impediments Although limited in terms of geographic scope and user participation, wireline and wireless cable network trials and full-scale implementations demonstrate the effectiveness of broadband cable networks Cable network configurations foster... enabling broadband cellular applications in fields that include education, government, medicine, and business Wireless technologies and networks such as WPANs (Wireless Personal Area Networks) , WLANs (Wireless LANs), WMANs (Wireless MANs), and WWANs (Wireless WANs) initially developed apart from cellular technologies and solutions In the present-day deregulated telecommunications environment, wireless networks . and broadband voice, video, and data delivery must also be conducted. 7. 16 WIRELESS CABLE NETWORKS 7. 16. 1 F EATURES AND FUNCTIONS Advances in technology and demand for fast access to broadband networks. (Asynchronous Digital Subscriber Line) networks in supporting access to broadband networks from SOHO venues. As noted in Chapter 6, ADSL is a high- speed broadband residential access technology. OPERATIONS MMDS implementations that operate in licensed spectrum between the 2.5 96 and 2 .64 4 GHz frequencies and between the 2 .68 6 and 2 .68 9 GHz frequencies are deployed in countries that include Ireland,