The dawn of the Wireless LAN (WLAN) and cellular convergence age is approaching.
There are about 29 million subscribers to these networks in the U.S. and almost 55 million worldwide.
The market for Wi-Fi and cellular services is expected to reach US$1.6 billion by 2010 in the U.S.
However, the converged network still faces many challenges, according to a panel of Wi-Fi and cellular convergence experts who spoke during last month’s Fall Intel Developers Forum (IDF) in San Francisco.
“The Wi-Fi network has got to support many voice calls at once [while] at the same time other traffic is going on.
“It has got to make sure the experience of voice is a good one,” said Graham Smith, vice-chair, Voice Over Wi-Fi Task Group, during the IDF panel discussion entitled “Wi-Fi is everywhere! Interoperability for Wi-Fi converged devices.”
Smith said one of the reasons why a converged network is beneficial is the coverage area is greater with no need to build extra cellular towers.
The importance of convergence between the two networks is it allows a user to be able to carry on a conversation on a cellular network, which then can be handed off to a WLAN access point without the call being dropped either with Session Initiation Protocol (SIP) or ultra wide-band (UWB) standards.
As well, quality of service is essential when it comes to the voice experience, Smith said, as is admission control and bandwidth management.
“You want to make sure you don’t oversubscribe when you allow voice calls. This applies to the home and multi-media if you are going to allow video calls, You want to make sure everyone has a good experience so [admission control] is a mechanism of preventing over-subscription or degradation of existing traffic,” he said.
Smith’s fellow panelist, Stephen Shearer, chair, Wi-Fi/Cellular Convergence Technical Task Group, said the real challenge to convergence is the need to merge the different philosophies of the WLAN and cellular industries. He said traditionally cellular has been very focused on radio frequency while WLAN has been interoperability focused. Shearer added WLAN needs to adopt radio frequency testing methodologies.
“There is some merging of philosophies that need to be happen there and we need to work with cellular organizations so we can build one test plan [for Wi-Fi cellular convergence],” said Shearer.
Also, he said there are special requirements when it comes to cellular integration.
“As we move into this type of environment we don’t have good transmission power, good sensitivity and we need to account for antennae loss, which in small cellphones can be quite significant.”
Shearer added that carriers will be the new customers for Wi-Fi but Eddie Chan, mobile/personal computing reasearch analyst with IDC Canada said it is task groups like Shearer’s and Smith’s that want carriers to be the new customers.
“They want [carriers] as a customer because they are not convinced. Carriers have invested millions in their own 3G networks. Why would they want to promote an alternative transport than their existing infrastructure they have invested in so heavily?” said Chan.
The target for the first WLAN/cellular certification is March 2006 and will initially apply to the home and small office. Certification for the enterprise will come at a later date.
“You can’t do certification for enterprise unless you have this fast handoff relating between two access points,” Chan said.
Chan sees a converged Wi-Fi/cellular network as something that is ready to go to market now and will work when mobile-WiMax arrives sometime in 2008.
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