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Polycom's Ben Guderian on WLAN Voice and Mobile UC

The great thing about Ben is that while he is consistently at the forefront of what's going on in the area, he never loses contact with reality. He'll give you the rundown on the hottest topics in the Wi-Fi Alliance, but he'll follow that with the real-world view and a sober assessment of the marketplace. I've known Ben for years, and I had the chance to talk with him recently regarding his views on developments in the WLAN voice market, wireless LAN standards, and other trends like fixed mobile convergence and mobile unified communications.

The WLAN Voice Market: While there is considerable interest in fixed mobile convergence and cellular-based mobile UC solutions, the market for voice devices that operate over wireless LANs is not going away anytime soon. The market is growing at a healthy 20%+ per year, and there will always be a core of users whose mobility range is limited to the campus (the "corridor warrior"), and WLANs provide a very cost effective way to serve that population. WLAN voice continues to be focused on a few core vertical markets, where it is now becoming entrenched. Health care has always led the way, and WLAN voice is now a standard tool for health care workers. In the retail segment, they are seeing expansion from the traditional big-box retailers into a more diverse set of retail outlets.

WLAN Standards: There has been considerable activity on the WLAN standards front, and here's what Ben sees coming from some of the major initiatives:

  • 802.11r Fast Basic Service Set Transition: This is the long-awaited and recently ratified Wi-Fi roaming standard, but Ben looks at it in his typical unflappable fashion--it's a good thing. He's quick to point out that while the standard is a solid move, WLAN infrastructure vendors have been supporting fast, secure handoffs for years, so 802.11r is not fixing any problem that has been a show-stopper for WLAN voice. He is waiting for the Wi-Fi Alliance's enterprise voice certification (in which Polycom is participating), as that will give enterprise-oriented VoWLAN vendors a solid framework going forward.

  • 802.11e/Wi-Fi Multimedia Quality of Service: SpectraLink had developed one of the first QoS mechanisms for wireless LANs with their SpectraLink Voice Priority (SVP) capability, which was supported on a wide range of WLAN access points as well as on their handsets; Polycom refers to those compatible access points as VIEW certified. They are incorporating the standards-based approach in their designs, but at the moment there appear to be more handsets still using the SVP approach. Their new Polycom 8002 handset supports only the WMM option.

  • 802.11n Radio Link: While they are not anticipating an 802.11n handset for a year or more, that too will find its way into the product line. The problem with 802.11n has been the power requirement, which is a major issue for mobile handsets. Ben notes there is an 802.11n option for voice handsets that uses a single transmit chain, thereby reducing the power requirement. However, he points out that the major benefit of 802.11n will be the capacity increase it provides, but that increase is negligible if the device supports only one transmission chain.

    Voice Compression: One anomaly about WLAN voice is that it has failed to capitalize on one of the fundamental efficiency features in VoIP, voice compression. You might think that with the limited capacity available on WLANs, techniques that use those resources more efficiently would be a natural. However, Ben is seeing little uptake on compressed voice in WLANs. Here's why: G.729 can reduce the voice payload from 64 Kbps to 8 Kbps in each direction, but with the amount of overhead involved in WLAN voice, the resulting increase in the number of simultaneous voice calls handled is only about 15%.

    Mobile UC: The mobilization of unified communications is an area where Ben sees some tremendous potential with VoWLAN technology. The industry wide migration to SIP is making it far easier for companies like Polycom to develop solutions that interoperate with any vendor's wired system. This also allows WLAN handsets to operate without the use of gateway devices that sit between the WLAN voice environment and the wired IP PBX network.

    He also sees a lot of synergy from integrating the location ability of WLAN devices with the presence server. WLAN location systems can resolve the user's location down to a few meters, and that information can be used to intuitively adjust their presence status. For example, if the WLAN can determine that a user is in a conference room, we might be able to change their status to "In meeting", or at least prompt them to determine if that is indeed their status. That same idea can be used when we determine that a user returns to their office. Few users will have the discipline to update their presence status manually, so location-driven solutions can add considerable value to presence.

    Using location as an input to the presence system is a natural, but Ben is looking at other location-driven capabilities. For example, if we determine that the user is on the factory floor we might increase the ring volume of their mobile device. Similarly, if the user is in that noisy environment, the system might automatically convert their voicemail messages to text.

    Mobility is a key element in unified communications, and while much of the interest has centered on cellular or dual mode Wi-Fi/cellular solutions, there are still lots of workers for whom intra-premises mobility is all that's required. Any solution that will depend wholly or partially on WLAN voice can benefit from the insight that Polycom brings to the area.

  • 802.11e/Wi-Fi Multimedia Quality of Service: SpectraLink had developed one of the first QoS mechanisms for wireless LANs with their SpectraLink Voice Priority (SVP) capability, which was supported on a wide range of WLAN access points as well as on their handsets; Polycom refers to those compatible access points as VIEW certified. They are incorporating the standards-based approach in their designs, but at the moment there appear to be more handsets still using the SVP approach. Their new Polycom 8002 handset supports only the WMM option.

  • 802.11n Radio Link: While they are not anticipating an 802.11n handset for a year or more, that too will find its way into the product line. The problem with 802.11n has been the power requirement, which is a major issue for mobile handsets. Ben notes there is an 802.11n option for voice handsets that uses a single transmit chain, thereby reducing the power requirement. However, he points out that the major benefit of 802.11n will be the capacity increase it provides, but that increase is negligible if the device supports only one transmission chain.

    Voice Compression: One anomaly about WLAN voice is that it has failed to capitalize on one of the fundamental efficiency features in VoIP, voice compression. You might think that with the limited capacity available on WLANs, techniques that use those resources more efficiently would be a natural. However, Ben is seeing little uptake on compressed voice in WLANs. Here's why: G.729 can reduce the voice payload from 64 Kbps to 8 Kbps in each direction, but with the amount of overhead involved in WLAN voice, the resulting increase in the number of simultaneous voice calls handled is only about 15%.

    Mobile UC: The mobilization of unified communications is an area where Ben sees some tremendous potential with VoWLAN technology. The industry wide migration to SIP is making it far easier for companies like Polycom to develop solutions that interoperate with any vendor's wired system. This also allows WLAN handsets to operate without the use of gateway devices that sit between the WLAN voice environment and the wired IP PBX network.

    He also sees a lot of synergy from integrating the location ability of WLAN devices with the presence server. WLAN location systems can resolve the user's location down to a few meters, and that information can be used to intuitively adjust their presence status. For example, if the WLAN can determine that a user is in a conference room, we might be able to change their status to "In meeting", or at least prompt them to determine if that is indeed their status. That same idea can be used when we determine that a user returns to their office. Few users will have the discipline to update their presence status manually, so location-driven solutions can add considerable value to presence.

    Using location as an input to the presence system is a natural, but Ben is looking at other location-driven capabilities. For example, if we determine that the user is on the factory floor we might increase the ring volume of their mobile device. Similarly, if the user is in that noisy environment, the system might automatically convert their voicemail messages to text.

    Mobility is a key element in unified communications, and while much of the interest has centered on cellular or dual mode Wi-Fi/cellular solutions, there are still lots of workers for whom intra-premises mobility is all that's required. Any solution that will depend wholly or partially on WLAN voice can benefit from the insight that Polycom brings to the area.

  • 802.11n Radio Link: While they are not anticipating an 802.11n handset for a year or more, that too will find its way into the product line. The problem with 802.11n has been the power requirement, which is a major issue for mobile handsets. Ben notes there is an 802.11n option for voice handsets that uses a single transmit chain, thereby reducing the power requirement. However, he points out that the major benefit of 802.11n will be the capacity increase it provides, but that increase is negligible if the device supports only one transmission chain.

    Voice Compression: One anomaly about WLAN voice is that it has failed to capitalize on one of the fundamental efficiency features in VoIP, voice compression. You might think that with the limited capacity available on WLANs, techniques that use those resources more efficiently would be a natural. However, Ben is seeing little uptake on compressed voice in WLANs. Here's why: G.729 can reduce the voice payload from 64 Kbps to 8 Kbps in each direction, but with the amount of overhead involved in WLAN voice, the resulting increase in the number of simultaneous voice calls handled is only about 15%.

    Mobile UC: The mobilization of unified communications is an area where Ben sees some tremendous potential with VoWLAN technology. The industry wide migration to SIP is making it far easier for companies like Polycom to develop solutions that interoperate with any vendor's wired system. This also allows WLAN handsets to operate without the use of gateway devices that sit between the WLAN voice environment and the wired IP PBX network.

    He also sees a lot of synergy from integrating the location ability of WLAN devices with the presence server. WLAN location systems can resolve the user's location down to a few meters, and that information can be used to intuitively adjust their presence status. For example, if the WLAN can determine that a user is in a conference room, we might be able to change their status to "In meeting", or at least prompt them to determine if that is indeed their status. That same idea can be used when we determine that a user returns to their office. Few users will have the discipline to update their presence status manually, so location-driven solutions can add considerable value to presence.

    Using location as an input to the presence system is a natural, but Ben is looking at other location-driven capabilities. For example, if we determine that the user is on the factory floor we might increase the ring volume of their mobile device. Similarly, if the user is in that noisy environment, the system might automatically convert their voicemail messages to text.

    Mobility is a key element in unified communications, and while much of the interest has centered on cellular or dual mode Wi-Fi/cellular solutions, there are still lots of workers for whom intra-premises mobility is all that's required. Any solution that will depend wholly or partially on WLAN voice can benefit from the insight that Polycom brings to the area.

    Voice Compression: One anomaly about WLAN voice is that it has failed to capitalize on one of the fundamental efficiency features in VoIP, voice compression. You might think that with the limited capacity available on WLANs, techniques that use those resources more efficiently would be a natural. However, Ben is seeing little uptake on compressed voice in WLANs. Here's why: G.729 can reduce the voice payload from 64 Kbps to 8 Kbps in each direction, but with the amount of overhead involved in WLAN voice, the resulting increase in the number of simultaneous voice calls handled is only about 15%.

    Mobile UC: The mobilization of unified communications is an area where Ben sees some tremendous potential with VoWLAN technology. The industry wide migration to SIP is making it far easier for companies like Polycom to develop solutions that interoperate with any vendor's wired system. This also allows WLAN handsets to operate without the use of gateway devices that sit between the WLAN voice environment and the wired IP PBX network.

    He also sees a lot of synergy from integrating the location ability of WLAN devices with the presence server. WLAN location systems can resolve the user's location down to a few meters, and that information can be used to intuitively adjust their presence status. For example, if the WLAN can determine that a user is in a conference room, we might be able to change their status to "In meeting", or at least prompt them to determine if that is indeed their status. That same idea can be used when we determine that a user returns to their office. Few users will have the discipline to update their presence status manually, so location-driven solutions can add considerable value to presence.

    Using location as an input to the presence system is a natural, but Ben is looking at other location-driven capabilities. For example, if we determine that the user is on the factory floor we might increase the ring volume of their mobile device. Similarly, if the user is in that noisy environment, the system might automatically convert their voicemail messages to text.

    Mobility is a key element in unified communications, and while much of the interest has centered on cellular or dual mode Wi-Fi/cellular solutions, there are still lots of workers for whom intra-premises mobility is all that's required. Any solution that will depend wholly or partially on WLAN voice can benefit from the insight that Polycom brings to the area.