UMA in the Office
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Unlicensed Mobile Access (UMA) is a fixed/mobile convergence (F/MC) technology that lets carriers control calls made with dual-mode handsets. Specifically, a carrier like T-Mobile can sell a phone with GSM and Wi-Fi support inside, and the phone can make a call on either kind of network.
This has limited UMA thus far to use by consumers. The wireless LANs in a big business which could benefit from the calls being made on the WLAN couldnt really support it due to the hand-off issues as mobile users move from one access point to another. The time it takes is usually just enough that the phone would de-associate and try to connect to the cellular network, then have to re-associate with the next nearest AP.
Enter Extricom. The company sells 8 and 24-port WLAN switches and made claims to Kineto one of the developers and biggest cheerleaders of the UMA technology that it could deliver UMA to the enterprise.
Kineto didnt believe it.
That opinion apparently changed when Extricom gave a live demo in Kinetos offices. It connected three access points to an Extricom switch, made a call with a UMA phone, and then one-by-one unplugged the APs. Using the visual interface for the switch everyone could see the connection jump from one radio/AP to another, because the phone saw them all as being the same.
Because each radio is listening to the UMA unit, all the radios look like one AP, and the phone doesnt know anything happened. Its seamless to the phone, says Steve Shaw, the director of marketing for Kineto. Shaw says other switch vendors
like Meru and Aruba require a secret sauce on the handset. [Meru disputes Shaw's original statement. Shaw told Wi-Fi Planet that, to date, testing with Meru equipment as been inconclusive, though tests with Cisco and Aruba both do indicate a need for "secret sauce" on the handset. Meru is now promising to meet with Kineto to finish such tests in the very near future. -- Edited 12/8/2006] And thats something he feels the carriers like T-Mobile which is experimenting with a UMA trial in Seattle wont touch. They dont want proprietary technology.
Extricoms vice president of corporate marketing David Confalonieri says the secret for his company is that the client on the network associates to the switch, not the radio/AP. The APs are nothing but an antenna, an RF jack. You install a zone of channel 1 APs we call it the channel blanket that provides contiguous coverage for just that channel from all APs. As the client moves, it never experiences de-association or re-association. Confalonieri says most of the competition in the switch market treats the network like each AP is a cell site with its own channel (the exception being Meru Networks which is similar but still requires some de- and re-association.)
By definition in the 802.11 specification, all the decision-making on connections is with the client, says Confalonieri. If the client moves, itll go through the cycle of scanning channels and de-association and re-association. Thats what the single-channel blanket from Extricom prevents. The client doesnt know theres three to ten APs, it just sees the channel and sees its relationship with the switch.
The IEEE 802.11 Working Group is working on a specification called 802.11r that will handle fast hand-off/roaming for Wi-Fi in the future, but it may take a long while for it to appear. Even if it works well, Kinetos Shaw says Leaders in the space sometimes poo-poo 11r getting the job done, because they want their secret sauce to handle it. I think 11r will probably work.
Extricoms switch, if it is all it's cracked up to be, wouldn't be a boon just for UMA. It could even help competing technology. Divitas Networks has created products with a similar effect for end-users, but one that puts the enterprise IT people in control of the system instead of the carriers. Divitas likens it to the difference between a PBX system in-house and a hosted Centrex to run corporate phones. Divitas has a deal with Symbol, and does require a bit of client software to be running on handsets.
The work between Extricom and Kineto is not business-oriented as yet, just technological, where the two companies will each serve as the others advocate, says Confalonieri.
Kineto is also a partner with Aruba Networks, which announced a five-phase plan in November for enhancing enterprise F/MC. Phase four, in fact, covers integration with carriers. Of this latest announcement from Kineto and Extricom, Aruba's co-founder and vice president of product management and marketing, Keerti Melkote, says, "Focusing just on hand-off is too myopic. Quality of Service, battery life, scale, security, and reliability are another set of holistic issues to deal with."
Melkote says Aruba works with handset vendors to improve battery life by five or six times the norm when connected to a standard Wi-Fi AP. Aruba plans to issue client specifications to carriers to help them build handsets that work better with WLANs by implimenting technologies like 802.11r and others.
Aruba today announced a joint sales and marketing deal with Japanese VoIP vendor OKI, to bring its WLAN to Japan in support of OKI's IP-PBX products.