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SPAY016—March 2004White PaperAR7VWi – A Highly-Integrated Broadband Residential GatewayPlatformWilliam C. Timm, William Santini and Luis MirantesBroadband Communications GroupTexas InstrumentsIntroductionAdvancements in silicon and systems integration have led to the development of a newgeneration of broadband residential gateway platforms that also support voice. This newgeneration of platforms not only eases the deployment of DSL-based residential gateways butalso provides new opportunities for the service provider to derive additional value from thealready deployed copper infrastructure.While many analysts do not foresee the residential gateway market gaining more than 30 percentof the broadband market share until 2007, and this market share does not include voice, there areseveral indicators that voice-enabled gateways could grow more rapidly than analysts predict.Some of these indicators include: 1.) the success of voice-enabled broadband services in the fareast, particularly Japan; 2.) the increased number of RFPs for voice-enabled broadband servicesthroughout the world; 3.) the recent success of broadband voice service providers includingVonage; and 4.) the accelerating rate of customer loss by telcos is forcing them to offer enhancedbroadband services via the telephone twisted pair.Setting a new precedent in this evolving market, Texas Instruments’ AR7VWi is a highlyintegrated, voice-enabled residential gateway platform that is positioned to enhance the user’sbroadband experience. Encompassing three core competencies of the Texas InstrumentsBroadband Communications Group, AR7VWi is the first product of its kind to integrate DSL,802.11b/g WLAN and VoIP on a single motherboard for a cost-effective and highly-differentiatedproduct.

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformFigure 1 – AR7VWi Block DiagramThe fundamental components of the AR7VWi platform include: TNETD7300A (AR7) – The single-chip DSL PHY/router. The TNETD7300A supports the followingDSL standards: ADSL1, ADSL2, ADSL2 , Annex A and Annex B. The TNED7300A also contains aTMTMMIPS32 4KEc 32-Bit RISC processor, a hardware ATM SAR, an internal Ethernet PHY withAuto-MDIX, and an internal power management module.SDRAM/FLASH memory subsystem – The memory subsystem is configurable depending uponthe specific application requirements.TNETV901 – The TNETV901 Voice Digital Signal Processor contains a TMS320C55x DSP coreand embedded memory for performing voice and fax processing over IP.FXS/FXO telephony interface subsystem – The FXS telephony interfaces directly support one ormultiple standard telephone devices that can be used for VoIP over the packet network or traditionalcircuit switch voice calls over the PSTN via the FXO interface.FXS to FXO bridging – The failover relay provides lifeline emergency telephone service to thePSTN in the event of power failure.Filter – The built-in inline filter eliminates interference of the POTS FXO circuit into the DSL.TNETW1230 – The TNETW1230 is the WLAN baseband digital processor.TNETW2522M – The TNETW2522M is a single-chip 802.11b/g radio with an integrated poweramplifier.RC2621 – The RC2621 is an optional second-stage power amplifier with an integrated receiversensitivity gain section that increases the overall output power to 1 Watt (as measured at thetransmit/receive switch).On-board 802.11b/g antenna – The design supports an on-board 802.11b/g antenna, an externalwhip antenna, or both, providing antenna diversity for 802.11b.SPAY016—March 20042

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformFeatures of the AR7VWi PlatformThe AR7VWi is implemented as a single-sided, four-layer printed circuit board.The overall bill of materials of the AR7VWi platform is minimized through integration of manydiscrete components into the above listed silicon devices. The smallest achievable form factor ofthe AR7VWi is only constrained by the mixture of connectors and indicators.Some options available on the AR7VWi platform include: Four-port Ethernet switchAdditional FXS ports (more than two simultaneous FXS operations may require additionalTNETV901s)Drivers for several common FXS/FXO device suppliersDSL dying gasp stuffing optionAdvanced AR7VWi ApplicationsThe capabilities of the AR7VWi broadband residential gateway platform allow for some highlyadvanced applications beyond just typical DSL, WLAN access points or VoIP. Benefiting fromthe fact the AR7VWi platform also connects to a PSTN line by nature of the DSL connection,some of these applications can provide a competitive advantage over equivalent cable modemservices. Also, given the inclusion of a powerful MIPS-based RISC processor and a WLANconnection, these services can be managed from virtually anywhere in the home through an easyto use web-GUI management interface.SPAY016—March 20043

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformFigure 2 – AR7VWi Web-based GUI Interface (Figure 2 shows an example of the Web-basedGUI interface that is provided with AR7VWi.)The following paragraphs elaborate on some of these applications and services that are possiblewith the AR7VWi platform: Single-port voice gateway with VoIP call forwarding – Given the AR7VWi can supportboth VoIP and connection to the PSTN via the FXO interface, AR7VWi can operate as asingle-port voice gateway with VoIP call forwarding capability. For example, whenproperly configured, the AR7VWi platform can forward VoIP calls to a cell phone or anyother number the user selects essentially creating a VoIP “follow me” service. Of course,when providing any type of call forwarding capability, it is always necessary to guardagainst the possibilities of fraud, which could be largely avoided by only allowing callforwarding to a single or short list of numbers. Home PBX – By taking advantage of the software capabilities of a resident MIPS RISCprocessor, an underlying Linux -based operating system and an extensible memorysystem, many PBX features could be made available in the home at little additional cost.Some of the capabilities might include detailed call reports, most cost-effective call routingvia VoIP or the PSTN, call screening, direct inward dialing to the desired extension,SPAY016—March 20044

AR7VWi – A Highly-Integrated Broadband ResidentialGateway Platformdistinctive ringing based upon number dialed or ANI, VoIP/PSTN call waiting and manymore. These services are easily managed with Web-UI via any Ethernet or Wirelessconnection. Network-based voice messaging – Lending to the fact that AR7VWi is connected to abroadband interface, either PSTN or VoIP originated voice messages can be stored andforwarded to a broadband network, making them retrievable anywhere in the network.This same capability can also be enhanced to provide a remote message indicatorthrough the network when there is a message available. VoIP to PSTN multi-party conferencing system – By taking advantage of simultaneousconnections to both the PSTN and VoIP, it is possible to provide multi-party conferencingbetween both networks. In addition, via in-band or out-of-band signaling using a DTMFkeypad or keyboard, the user could control an individual’s volume or muting. Work-at-home distributed call center with broadband data access – Using the PSTNto receive calls forwarded from a call center, the call agent can talk to customers whileobtaining customer data via the broadband connection. In addition, the call center cansimultaneously track the agent’s activity via messaging over the broadband connection.Statistics can be maintained on each agent and the agent can “busy out” when breaks areneeded all through the network. Finally, using a single-direction VoIP call, a supervisormay chose to listen in on an agent’s activity without the agent knowing, or calls can berecorded and immediately forwarded to the network through the network-based voicemessaging discussed above. Multi-line home network with life-line failover – Probably one of the most beneficialfeatures of the AR7VWi platform is the ability to effectively support multi-line capabilitiesover a single twisted pair. The multiple voice lines would actually be carried over VoIP tothe central office. Of course, this may require termination of the VoIP calls at the centraloffice. In the event of a power failure, the relay would disengage and directly connect theFXS lines to the PSTN.SPAY016—March 20045

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformVoice FeaturesThe voice features of the AR7VWi are built upon the industry-leading Telogy Software voicetechnology platform. The Telogy voice technology platform is based upon years of VoIPexperience that provides the industry’s highest quality and most fully-featured VoIP capabilities.The following table lists the fundamental features of the Telogy voice technology platform.Table 1 - Telogy Software VoIP Features in AR7VWiDSP type:Frame sizes:Build type:Channels:Codec(s):Telephony signaling:Caller ID generate/detect:Fax relay:Fax modem:Fax protocol:Miscellaneous features:Echo cancellation:Voice activity detection:Tone generation/detection:Tone relay:Packet loss concealment:Peer-to-peer:PCM hardware interface:SPAY016—March 2004vDSP5/5.5/10/20/30 msVoice/fax2 LBRC 1 PCMG.711, Appendix 1, 2G.726G.729ABG.723.1AMGCP, SIP, H.323Bellcore, ETSI, UK, ChineseRFC-2833v.21, v.27ter, v.29, v.17T.38UConferencing supportCall waitingCall transferVoice mail indicationGain controlCodec switchoverAsymmetric codecs (Rx/Tx)Configuration provisioning32 msG.168NLPDouble talk detectionNoise level matchingAdaptive levelSID supportPink CNGG.711 Appendix 2DTMFv.21 faxv.25 modem/faxCall progress tonev.18ACNG, fax calling tone 1100 HzDTMF/MF relayDTMF RTP relay (RFC-2833)G.711 Appendix 1RFC-2833, AAL2 (UUI)µ-Lawa-LawLinear6

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformDSL FeaturesAR7 has been designed to achieve the lowest possible bill of materials while still supporting allADSL standards at the highest possible performance. AR7 can be used in applications fromsimple, integrated bridge/routers, as shown in Figure 3, all the way up to advanced voice enabledgateways. Some of the key performance features are discussed in more detail in other whitepapers and technical briefs. The following is a list of key features of AR7: Future proof ADSL - all standards on one chipo Annex A, B, I, J, L, Mo ADSL2/ADSL2 /READSLVxWorks PSP and complete Linux NSP software solutionProven industry leading interoperability and performanceo Worldwide interoperability footprinto Dynamic Adaptive Equalization (DAE) enhances performance and improvesinteroperability Switchable hybrid Programmable transmit and receive filters Echo cancellation Configurable equalization structuresIntegrated line driverIntegrated power managementLowest BOM cost of any ADSL solutionIntegrated Ethernet 10/100BaseT PHYADSL SubsectionSwitchableHybrid Increased Reach Increased Rates TNETD7300 True Single Chip Integrated Ethernet Integrated USB Integrated Power Mgt. True ADSL2/ADSL2PlusS/W upgrade – no H/WchangesStandard MemoryADSLTransformer Single designoptimized forADSL/ADSL2/ADSL2Plus/RE-ADSL 2M Flash 8M SDRAMPower Subsystem: Single Voltage Reg.Figure 3 – Basic Bridge/Router based on AR7SPAY016—March 20047

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformDAE is a key feature of AR7 and is largely responsible for AR7 setting new ADSL performancestandards, including meeting the new DSL Forum WT-085 performance bar. Because of theimproved performance of AR7, it is actually being leveraged by service providers to increase therange and coverage area served.One of the key performance features of AR7 related to DAE is a “switchable hybrid” that matchesthe impedance of the hybrid to the line. This feature greatly enhances the performance in thepresence of bridge taps or unruly house wiring.For a complete description of all the DAE features, please read the Dynamic AdaptiveEqualization Technical Brief.As mentioned above, the AR7 software packages includes support for both Linux and VxWorks.While the features for VxWorks are individually licensed from WindRiver, the Linux features aresupported directly through Texas Instruments via a standard Monta-Vista license distribution.The Linux-based Networking Support Package (NSP) for AR7VWi provides the followingfeatures: Bridging Routing (RIP v1/2, IGMP proxy, IP forwarding, MAC encapsulation) WAN protocols (PPPoA, PPPoE, RFC 1577) Address translation and securityo NAT/NATPo UPnP Internet Gateway Device (IGD)o ALGso Stateful inspection firewallo Denial of serviceo Filtering Gateway serviceso DHCP client/server/relayo DNS relay/proxyo Syslog Network managemento Customer extendible configuration managero Web server and reference Web pageso SNMP SETs and traps for four groups in MIB-II onlyo Command Line Interface (CLI) for NSP & WLAN. Will keep VoP CLI.o Telnet, FTPSPAY016—March 20048

AR7VWi – A Highly-Integrated Broadband ResidentialGateway Platform Othero WLAN user isolation for added security in hot-spot and multi-family dwellinginstallationso VLAN tagging per PVCo SNTP with DHCP optionso New memory-saving Web UIo Firewall support for voice signaling and media streamso Voice & IP QoS integrationo Extended bridge filtering with per-port rules Diagnostics and test capabilitiesWLAN Features and ApplicationsTests of Texas Instruments’ latest WLAN products show a clear lead in rate and reach over othercurrent suppliers. Texas Instruments designs WLAN products knowing that better range meansmore awards and fewer support calls from customers and a better end-experience for customers.AR7VWi has incorporated several new WLAN features that are not present in previous designs.These features include: 802.11b/g integrated right on the motherboardUse of the TNETW2522M (RC2522M) to simplify and cost reduce the radio designFuture stuffing option for the RC2621 second-stage power amplifier that effectivelydoubles the range of 802.11b/gMotherboard layout includes an on-board antenna as well as connection to an optionalexternal antennaFigure 4 shows the comparison of the radio design between the previous generation and theAR7VWi version using the TNETW2522M (RC2522M). Use of the TNETW2522M eliminates RFinterconnects sensitive to layout and PCB, thereby significantly reducing customer layout issues.In addition, use of the TNETW2522M reduces the number of components to less than 35components in the radio subsystem. The TNETW2522M uses a 6 mm x 10 mm QFN-likepackage.SPAY016—March 20049

AR7VWi – A Highly-Integrated Broadband ResidentialGateway Platform2400 – 2500 MHzBand Pass Filters2400 – 2500 MHzBand Pass FiltersRC2326RC2522M2100 MHzLO traces374 MHz SAW374 MHz SAWRC252240 MHz XTALFigure 4 – Comparison of 802.11 radio design using the TNETW2522MThe entire 802.11b/g design consumes less than three square inches on the AR7VWimotherboard. Figure 5 shows a photo of this layout. The bottom right corner of this layoutincludes an on-board antenna that can be used as the only antenna required for 802.11b/g or, forgreater performance, an external antenna may be used. In addition, both the on-board antennaand the external antenna can be used simultaneously for 802.11b antenna diversity.The layout also shows the location of the RC2621 power amplifier in the bottom right. Theaddition of the RC2621 can boost the power up to 1 Watt, thereby overcoming issues withdeployment in difficult homes or multi-family dwellings. Figure 6 on the next page shows therelative performance of 802.11g at 54 Mbps with the RC2621.Figure 5 - 802.11b/g layout for AR7VWiSPAY016—March 200410

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformFigure 6 – Performance Improvements of 802.11g with the RC2621SummaryIn summary, the AR7VWi design offers many unique opportunities to offer advanced applicationsnever before realized in a single, integrated platform. In addition, there are many key featuresthat aid in easing the deployment of both DSL and WLAN. These features extend the customerservice area for DSL and ease the deployment of 802.11 in difficult homes. These characteristicsprovide a powerful combination that should be appealing to both the service provider and enduser. The end result could potentially change the analyst’s view of voice-enabled residentialgateways to an earlier and more rapid market growth.SPAY016—March 200411

AR7VWi – A Highly-Integrated Broadband ResidentialGateway PlatformVLYNQ, TMS320C55x and Dynamic Adaptive Equalization are trademarks of Texas Instruments. Telogy Software isa registered trademark of Telogy Networks, a Texas Instruments Company. All other trademarks are the property oftheir respective owners. 2004 Texas Instruments IncorporatedImportant Notice: The products and services of Texas Instruments Incorporated and its subsidiaries describedherein are sold subject to TI’s standard terms and conditions of sale. Customers are advised to obtain the mostcurrent and complete information about TI products and services before placing orders. TI assumes no liability forapplications assistance, customer’s applications or product designs, software performance, or infringement ofpatents. The publication of information regarding any other company’s products or services does not constitute TI’sapproval, warranty or endorsement thereof.SPAY016—March 200412

Vonage; and 4.) the accelerating rate of customer loss by telcos is forcing them to offer enhanced broadband services via the telephone twisted pair. Setting a new precedent in this evolving market, Texas Instruments’ AR7VWi is a highly-integrated, voice-enabled residential