Wifi Revolution

Voice over IP (VoIP) is no longer about “if” it will take off; rather, it’s about how quickly can it be adapted to various needs and circumstances. Among those challenges is increased quality for Voice over WiFi (News - Alert) (VoFi) services, which is integral to the increased awareness and adoption of IMS standards and infrastructures and fixed/mobile convergence (FMC) solutions.

 

Globally, the VoFi market will gain traction as dual mode handsets are improved. Indeed, Japan already has as many as 100,000 dual mode handsets in operation already, with evidence suggesting that users are keen on having a single device for use at home, on the road, and in the office. Even in North America and Europe, customers are talking more and more about a single device solution than about costs savings — a natural progression once the cost savings are made available to everyone.

 

Aruba Networks, which focuses heavily on the network edge — the point, in the FMC scenario, where a call has to pass seamlessly from a WiFi to a cellular network — announced several major new features and product enhancements designed to enhance its Voice over WiFi (VoFi) solutions.  The enhancements are part of the company’s overall roadmap for reaching what many agree is the holy grail of communications, true and complete fixed/mobile convergence (FMC).

 

Aruba’s latest features and plans, which comply with the latest WiFi Alliance standards, help its customers realize more than the basic requirements for untethered VoIP. Instead, Aruba has considered and addressed the current and future needs of advanced VoFi networks, including new levels of scalability and performance, as well as effective management tools to go along, all of which are required in order to migrate to a true FMC implementation. In fact, Aruba’s latest innovations are the second of its five-phase roadmap to FMC.

 

The initial phase included raising general awareness of Voice over WiFi and its benefits and its complications — it was really about making single mode handsets work well over WiFi, for which Aruba created its Voice Flow Classification (VFC) functionality to coordinate the flow of traffic across the network by uniquely identifying, classifying, and prioritizing traffic based on predetermined rules. Others, of course, have similar functionality in their networks, must most still separate the SIP layer from the WiFi layer, which tends to be considerably less precise than being able to consider all traffic together.

 

The second, current phase, is about scalability. In Japan, which is the current hotbed of VoFi, requests are for the ability to move from 500-phone installations to more than ten times that figure. To accomplish that, Aruba has been building a number of features, including new management features, which will most certainly be required with such scalability. In terms of dual mode technology, however, this phase still has little to do specifically with FMC — though it is all applicable to dual mode technology — and is more about making single mode devices work better, which will, ultimately, benefit the entire industry as it migrates to dual mode services.

 

“You can have fast handoffs or secure handoffs, but the trick is to get them both at once,” says Peter Thornycroft, senior product manager at Aruba. The latest enhancements take into consideration quality and management issues that are likely to present themselves in larger deployments as Aruba continues its drive to make the combination of hardware and network handover better, and more secure. 

 

Improved Quality of Service (QoS) — Full implementation of the WMM specification, plus additional enhancements, ensure consistency between the QoS level and traffic type and permit adjustments to the QoS level as appropriate, delivering voice packets within acceptable delay, jitter and loss parameters. In other words, Aruba has the capability not only to negotiate different levels of priorities, but also to ascertain whether a packet labeled “high priority” actually is such.

 

Increased Call Capacity — Full support for the WiFi Alliance’s TSpec protocol (which is akin to an RSVP system for calls) to allow increased control over the number of active voice calls on an access point (AP) at any given time, assuring bandwidth availability and better call quality, even as voice clients roam between APs. Aruba has been able to get as many as 76 calls on a single AP in a controlled environment.

 

Improved Battery Life — Because people have gotten used to their small form factor phones, batteries in dual mode handsets cannot be much larger. Improvements include full network-side implementation of WMM-PS, U-APSD and several enhancements, which together can improve talk time by a factor of two and sleep time by as much as five times, by extending sleep times and reducing unnecessary battery drains.  Aruba has been able to increase talk time up to four hours and standby time up to 120 hours.

 

Faster Handoffs — In many cases, dual mode phones have not yet been equipped with the latest state of the art algorithms for faster handoff. Opportunistic Key Caching (OKC) for both WPA2 and WPA clients saves considerable authentication time and reduces call interruption during handover between APs by limiting the number of frames that have to be exchanged at a new AP. The standard reference point tends to be 50ms, but Aruba is measuring handoffs in the 6ms range.

 

Significantly, the new features and enhancement are designed to 802.11 specifications, meaning that no client- or vendor-specific modifications are required to benefit from them. Aruba feels that supporting open standards with its innovations assures interoperability with industry leading and solutions and allows for customer choice rather than locking them into proprietary implementations.

 

This latest set of enhancements mean that Aruba is able to scale its solution to meet the needs of even the largest enterprises, such that it can move ahead with the third phase of its roadmap, enterprise integration.

 

As PBX vendors increasingly seek to introduce FMC capabilities to their products — and Aruba believes most major players in the PBX (News - Alert) space will have announcements to make within the next six months — the difficulty becomes simplifying the connection between the PBX and the cellular network. Ideally, this would be a vendor agnostic component, which is where Aruba finds itself. With just some software added, Aruba’s mobility controller can hand off calls between WiFi and cellular for dual mode phones in conjunction with the PBX — any PBX with which it has been certified. In this scenario, Aruba only becomes active in the call process when the mobility controller realizes a call is moving from WiFi range into cellular range; otherwise it’s purely in a monitoring state. 

 

“The continual monitoring means we can ensure the call is not dropped between networks,” says Thorycroft. “It’ll work with custom clients as well as off the shelf hardware, and we’re looking at a demo shortly after Christmas, with general availability in the first half of 2007.”

 

In fact, Aruba is already working closely with several leading PBX vendors to enable its Mobile Voice Continuity (MVC) features and tighter integration between the WLAN and PBX or SIP communication server.  To achieve maximum interoperability with the IP PBX, Aruba is developing an open application programming interface (API) that will be made available to IP PBX manufacturers, which will enable seamless handover, CAC, voice management, security, and E-911 integration and location functions.

 

Following its initial enterprise integration, Phase Four of Aruba’s roadmap will focus on carrier integration. There are already several mobile operators in the United States and Europe testing and deploying UMA services with consumers — T-Mobile, Orange, Telecom Italia (News - Alert), and TeleSonera — and the next logical step for them will be an enterprise push. When this happens, many of the features Aruba has focused on to date will play a critical role in extending services to the enterprise, including centralized architecture, QoS, call admission control, fast handover, adaptive RF, and remote management.

 

“Carriers will have a good go at this market, and they will have some serious advantages here, especially combined with their managed services offerings,” predicted Thornycraft. 

 

The uninvasive nature of Aruba’s platform, while providing end-to-end visibility into VoFi traffic — it essentially takes on security gateway functionality — makes it an ideal addition to service providers’ infrastructures. In fact, Aruba is already working with service providers and UMA equipment vendors to assure interoperability. 

 

Once both enterprises and carriers have been integrated into the VoFi world, the final phase entails ensuring seamless FMC for all IP-based services across any wireless network — cellular, WiFi, WiMAX, etc. For Aruba, this means integration with IMS-based approaches to delivering seamless networking across both carrier and enterprise networking. While that is still a few years away, at best, according to Thornycroft, every roadmap needs an ultimate destination, and a truly converged, truly mobile communications environment it that endpoint. “We’re a mobility company more than a WiFi company. WiFi happens to be the way it’s delivered today, but it could really be by any means, wired or wireless,” concludes Thornycraft.

 

 

 

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