Dual-mode devices have been touted as the be all and end all for the mobile workforce. Whether it's a corridor roamer looking for seamless connectivity on the Wi-Fi or cellular networks, or a true road warrior needing "anytime" connectivity on the road, dual-mode is being prescribed as the cure-all.
But dual-mode devices, out of the box, may not live up to the hype. They promise seamless connectivity to voice and data from both Wi-Fi and cellular, but few, if any, offer a true seamless mobile experience without a lot of extra time and work to make good on that promise.
"Out of the box, they don't do much of anything at all," said Current Analysis analyst Avi Greengart. "In the enterprise, you can get faster Web browsing on the corporate campus, but in most cases Wi-Fi is not set up for voice at all."
Greengart said some devices -- BlackBerry's new 8820 dual-mode model, for instance, or new dual-mode devices from Nokia -- use Wi-Fi for data only and aren't designed to accommodate the voice side without IT intervention and integration. He summed it up this way: "Some can't use Wi-Fi for data. Some can only use Wi-Fi for data. And some can use Wi-Fi for data and voice."
The goal of most companies when considering a dual-mode approach is to harness the ability to use both Wi-Fi and cellular for both voice and data applications. And that goal includes being able to hand off seamlessly between both networks without losing a call or connection. By definition, dual-mode means the device can use voice and data connectivity on both the cellular networks and through a corporate IP PBX.
Currently, T-Mobile offers a consumer-based option that hands off between Wi-Fi and cellular from a user's home wireless network or public hot spot. That model has not yet made its way into the enterprise, though it may do soon, Greengart said.
Whether the driver is saving money by not logging expensive cellular minutes and data costs, or ensuring connectivity where cellular service is lacking, companies are looking to the recent influx of dual-mode devices to take advantage of the "two birds with one stone" approach.
According to a recent study published by Infonetics Research, enterprise adoption of Wi-Fi phones is on the rise, driven by increased use of WLANs and IP PBXs. Adoption will be fuelled further by operators launching dual-mode services for fixed-mobile convergence (FMC).
Infonetics found that dual-mode Wi-Fi/cellular phone sales will rise at a compound annual growth rate of 31% from 2006 to 2010. In addition, seamless handover FMC phones are expected to represent 35% of the dual-mode phone market by 2010, compared with 3% last year.
When it comes to the dual mode market, Nokia was the strong leader in phone revenue in 2006, followed by Sony Ericsson and Motorola, Infonetics found. On the single-mode Wi-Fi phone side, SpectraLink (Polycom) led the pack, significantly beating out Linksys and Cisco.
From the Wi-Fi perspective, Greengart said, dual-mode devices offer little more than a speedier Web connection, meaning faster browsing while on a corporate campus or a home wireless network. To add voice to the mix, a client such as Skype or one from the Gismo Project would need to be installed, or the devices would need to be synced to a corporate IP PBX to offer Wi-Fi-based VoIP.
Last month, Avaya announced plans to pair with Nokia to enable Nokia's Eseries devices -- the E60, E61 and E70 models -- to link to Avaya's Communications Manager IP PBXs for voice over Wi-Fi, using Avaya's One-X Mobile Dual Mode Edition software. The Avaya and Nokia combination allows calls made to a user's desk phone to be received on Nokia Eseries devices. Inside corporate walls, the solution uses the company's Wi-Fi network, and the user, once outside, can hand off the Wi-Fi call to the cellular network by pressing a button without further interruption.
Along with Avaya, Nokia also supports Alcatel and Cisco dual-mode solutions to enable VoIP over Wi-Fi.
Overall, however, the dual-mode chasm is a pit of uncertainty where users and IT pros are looking for an all-in-one solution and ending up with more of a one-or-the-other approach, according to mobility experts.
"It's definitely not clear what you can and can't do," Greengart said, adding that most corporate device users are thrilled to have zippy Wi-Fi data connections on a mobile device, which somewhat band-aids the disappointment that voice over Wi-Fi isn't quite there yet or isn't available. "But even then you can make the case that it's not clear what they can and can't do," he said.
Still, Greengart said he's not accusing vendors of misleading companies -- yet.
"I don't think the technology is over-promising and under-delivering, yet," he said. "But you do have to do your research. And the notion of VoIP [on a dual-mode device], outside of some big services, is going to require a Skype client or something equivalent, or for IT to work to align the stars just right."
Kevin Oerton, director of Wi-Fi product marketing for BlackBerry manufacturer Research In Motion, said the company's new 8820 dual-mode device is looking to solve some of the user issues and uncertainty about dual-mode. The 8820 marks the first Wi-Fi-enabled BlackBerry that supports 802.11 a/b/g. It switches between Wi-Fi and EDGE/GPRS/GSM cellular networks and uses unlicensed mobile access (UMA) support for Wi-Fi voice.
"The user wants to focus on using the device, more than worrying about the user experience," Oerton said.
Essentially, he said, dual-mode users crave better coverage regardless of location and want to be able to interface with mobile applications and other features at Wi-Fi speeds.
"From a carrier perspective," he said, "Wi-Fi can extend coverage where the carrier can't reach."
Vivek Khuller, CEO and founder of DiVitas Networks -- maker of a network appliance that offers seamless voice and data mobility over Wi-Fi, the Internet and through dual-mode phones -- said most dual-mode device manufacturers flounder because they don't create devices that can handle the real-time nature of voice over Wi-Fi. In many cases, the processors can't tackle the demand of a VoIP client.
"A number of devices claim they're dual mode but are not optimised for voice," Khuller said. "The first generation of devices are optimised for data, and voice is an afterthought."
The DiVitas Mobile Convergence Appliance (MCA) converges Wi-Fi and cellular to let devices seek out the optimal network to route voice and data transmissions. Though there are some differences, Siemens offers similar functionality with its HiPath Mobile Connect Appliance.
The goal, Khuller said, is to offer "equal, secure and seamless access to applications like voice, IM and presence over any handset over any network."
Jack Gold, principal and founder of J.Gold Associates, agreed with Current Analysis' Greengart that vendors are not to blame for some of dual-mode's current shortcomings.
"The bottom line for all of these devices is they're only as good as the network," Gold said. "If you can't seamlessly switch from Wi-Fi to cellular, that's AT&T's or T-Mobile's fault. But the ideal dual-mode phone is one that doesn't cost me anything [when using Wi-Fi] and offers me fast access. But I don't want to have to play around; it's up to the network to figure it out."
Gold said the promise exists that dual-mode devices will turn the idea of an anywhere enterprise on its ear, but it's still a bit ahead of its time.
"Look at the Wi-Fi aspect just for data right now," he said. "The Wi-Fi is more for Web surfing."
Though vendors like Cisco and Avaya offer VoIP clients that work over Wi-Fi, they still require a level of manual switching between the networks, whether that means changing settings or hitting buttons.
"In the longer term, you want [dual-mode devices] to be VoIP enabled," Gold said, adding that the sweet spot for that trend is still a good three to five years out. "Right now, you're not going to be able to buy a seamless roaming, transparent service off the shelf. But the promise of dual-mode is real. There's some real benefit to it, and we're still early on the adoption and waiting for it to mature."