Seamless roaming, the ability to switch between Wi-Fi and cellular networks without loss of signal, will likely appear this year according to some major players in the wireless and cellular markets.
In 2003, industry vendors Motorola, Proxim and Avaya announced they would work together to create a set of standards-based solutions, both hardware and software, that would bring this ‘Holy Grail’ of wireless into reality. The goal is to put in place systems and have user-ready devices that will stay connected as people move between Wi-Fi or WLAN corporate networks and the larger public cellular networks.
Stephen Orr, director of client relations with Motorola Canada in Markham, Ont. said that seamless roaming has been tested and proven in limited roll-outs.
“For example, a large car manufacturer put in place a PBX (Private Brach Exchange) solution for its internal phone system that was designed to replace a normal wired phone system,” Orr added. “But it had the added benefit of when the user left the facility, the handset would roll over to the GSM (cellular) network. So we’ve proven it already and…the next step is to take it mainstream.”
Motorola’s CN620 cellular phone is made to switch between Wi-Fi networks and GSM cellular phone networks.
Orr says that seamless roaming and technologies like its CN620 phone are possible because several technical hurdles have been overcome recently.
“One of the things that had to be solved was the problem of battery life when you put a Wi-Fi chip set inside a cell phone which does not have a large battery,” said Lynn Lucas, vice-president of product marketing for Proxim Corp., a wireless network provider, in Sunnyvale, Calif.
Lucas said Wi-Fi solutions tend not be very power friendly. While not a problem when Wi-Fi is used in notebooks because of the notebook’s large battery, cellular phones present a greater problem.
As cellular phones became smaller so did the batteries and Wi-Fi networks tend to drain those batteries very quickly. The reason is Wi-Fi networks cannot tell a Wi-Fi-enabled device to power down when that device is close to the network. Cellular networks do that already but it was only recently that protocols were developed for Wi-Fi networks to do the same thing.
“Other interfaces that had to be developed were the ones for collaboration between the PBX ( or phone switch) and the device that is going to do the handoff between the Wi-Fi world and the cellular world,” Lucas said.
She continued by saying that these protocols are now being rolled out in the newest PBX solutions — so later this year it will be possible for someone connected a Wi-Fi network in a building to drive off to a meeting and have the phone switch automatically between the different networks with the PBX systems handling the change-over.
Frank LoVasco, mobility solutions practice leader for Avaya Corp. in Basking Ridge, NJ said when seamless roaming rolls out commercially in the New Year it will tap in to a growing need among corporate customers for improved enterprise performance and solutions. It is likely that corporate customers will use seamless roaming capabilities to get the same kind of telephony solutions and services available on an office desk phone delivered to handheld and cellular devices.
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