networkZONE Products for the week of April 12, 2004
Texas Instruments Says . . .
Cable Beater -- TI Challenges Cable Telephony With
AR7 DSL Router Designs That Integrate VoIP and Wi-Fi
Texas Instruments has introduced two new reference designs based on the AR7, TI's ADSL router-on-a-chip, to provide Voice over Internet Protocol (VoIP) and wireless home networking. The new designs combine key elements of TI's broadband portfolio which was strategically designed to allow future system-level integration with platforms containing common hardware and software architectures. This allows for low-cost integration of the AR7 with TI's 802.11b/g platform and voice DSP with Telogy Software to provide VoIP and WLAN capabilities to consumers.
The newest members joining AR7 and AR7W in the AR7 family are the AR7VWi and AR7V. The AR7VWi provides VoIP plus 802.11b/g wireless home networking while the AR7V provides VoIP over DSL. With the AR7 family manufacturers are able to develop complete DSL product lines that are operator quality and deployment ready, due to extensive testing in TI's Broadband labs and hardened through real world deployments.
Flexible, Integrated Solutions
The AR7 family enables manufacturers to quickly and easily deploy products
with significant cost reductions. With motherboard level integration of
these three systems, TI reduces the bill of materials (BOM) for VoIP DSL
systems. The AR7 family leverages TI's low cost VLYNQ chip-to-chip serial
interface to provide superior performance from the AR7 to the VoIP and WLAN
sub-systems. The family also leverages TI's common broadband hardware and
software architectures which maximizes reuse across product lines, further
decreasing costs for manufacturers.
"With our expertise, broadband portfolio and understanding of OEM and operator needs, TI is laying the perfect framework to take broadband to the next level of triple play services," said Greg Jones, general manager of TI's DSL Business Unit. "Adding reliable, proven VoIP and Wi-Fi capabilities to routers makes DSL services more attractive and will help operators add services to maintain and grow their subscriber base."
One Family -- Four Product Offerings
The AR7VWi and AR7V are complete hardware and software designs that combine
TI's leading ADSL router-on-a-chip, the AR7, with a voice DSP and Telogy
Software. The AR7VWi also integrates TI's TNETW1230 802.11b/g solution on
the motherboard for Wi-Fi home networking.
The new AR7 designs leverage TI's industry leading silicon and Telogy Software for VoIP, which represent over 80 percent of the total VoIP integrated circuit (IC) shipment volume. The solution incorporates a full implementation of voice features that include echo cancellation, voice packet playout software, tone processing, voice activity detection, and multiple low bit rate (LBR) voice codecs for bandwidth reduction.
The AR7 includes a Linux Network Support Package (NSP) that solves the challenge of providing Quality of Service (QoS) for voice. The advanced QoS implementation dynamically allocates the limited upstream bandwidth resources for optimum performance based on the ADSL line's capabilities. The NSP provides four priority queues to enable the superior quality levels of voice and data over the ADSL connection. Dynamic Packet Fragmentation optimizes the use of upstream bandwidth available for data traffic after the voice packets are prioritized.
With TI's 802.11b/g technology, the AR7VWi, like the AR7W, enables consumers to take full advantage of broadband content and applications from anywhere in the home without wires. The AR7VWi will take advantage of the 802.11g throughput enhancement and reach extension technologies that TI will be unveiling later this year. These will deliver the throughput consumers need for multimedia applications and longer network range to cover an entire house with the maximum bandwidth available.
The entire AR7 family takes advantage of the improved performance capabilities
offered by the AR7. The AR7 family supports all existing DSL standards,
including the new ADSL2 and ADSL2+ standards, enabling download speeds up
to 24Mbps.
analogZONE Says . . .
With the telcos and DSL providers struggling to deploy their own triple-play services before the cable companies can eat their lunch, TI support of VoIP is a welcome follow-on to its original AR7 DSL modem and integrated host system. Among the neat features I appreciate about this product is the abundant processing power provided by the on-chip RISC core to support security, routing, as well as whatever features you want to develop for your application.
TI is now adding the VoIP and Wi-Fi features they promised a year ago. As with the earlier verison, the C7 MIPS core handles call set-up call management, and QoS, and uses its TI-proprietary VLYNQ serial link to communicate with its companion C55 DSP which handles voice coding and tone generation.
One of the advantages of going with TI is that their Telogy group was one of the pioneers in VoIP and has invested many years and large chunks of resources in understanding how VoIP works in the "real" world. The result is a whole-system solution that works end-to-end instead of a set of disjointed protocol stacks and functions. In the process of refining their system, they've uncovered and solved several non-apparent issues that affect the QoS of a VoIP connection running over DSL connections. One of their more significant insights stems from the fact that most ATM-based DSL connections have only one VC provisioned, leaving two logical Ethernet connections (data and voice) to struggle to share for priority. Of course, the voice stream must have higher priority to meet latency requirements, but it must also deal with a narrower upstream "pipe" which often requires fragmenting packets for transport over the ATM network. Efficiently filling the pipe places serious demands on the host processor's routing stack as well as the lower-level drivers.
Adding Voice over WLAN to the equation further complicates matters. Now VoIP is terminated in the handset, but the gateway still must manage QoS issues between the CO and the handset. It must also negotiate handing off the IP stream to the 802.11 transceiver, which supports its own QoS mechanism across the WLAN. This means that the gateway must interact with 802.11's QoS mechanisms and coordinate their efforts. From my experiences in bridging other protocols, I imagine this is not very easy and believe TI when they say that getting the QoS issue right actually involves addressing a series of issues spread across the entire system. One example they pointed out involved getting their low-level I/O drivers to work in concert with the protocol stacks and voice-coding functions, and to avoid over- or under-running the small system buffers.
Another value-add that TI supplies is their reference design and development kit. It's a "one box" product that includes a gateway and supports all services. Because the AR7VWi offers manufacturers deployment-ready designs that are fully-tested and field-hardened customers get a head start on their development programs. The development board supports POTS fallback using either SiLabs or Legerity (included with board), but a mid-board header allows developers to add a line interface of their choice.
Besides solving many basic problems with voice QoS, the platform makes it easy to develop specialized call handling functions, firewalling, VPN support, and other value-add features. These features will become increasingly important to providers who will count on them to help cut both operational and capital costs. Then too, custom functions like home networking, security, access control, and telephony will help make their service "sticky" - i.e., more resistant to replacement by competitors.
I'll expect TI to have some initial success with its VoIP solutions in Japan because the all-you-can-eat model it enables is a clear, cheap alternative to the current, regressive measured/metered billing structure that the national PSTN's now enjoy. The unregulated environments in Asia -- most notably China and Korea -- are helping accelerate roll-out of low-cost IP-based voice services.
The same reasons will be driving strong demand in European countries which have not adopted a competitive telecom policy until now. I'm hoping that the US will follow, driven by cable data/DSL competition before it's too late. I'd really hate to have to trust my dial tone, and especially my 911 service, to the likes of Comcast or Liberty Media.
Full scale production is expected in June 2004. Total ODM BOM for gateway with VOIP & Ethernet only, will be about $65 - $70.
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