Clearing up fixed-mobile confusion

Fixed-mobile convergence (FMC) is supposed to bring various networks together for a seamless user experience, but the industry hasn't come together on how this technology will work. In this excerpt from Business Communications Review (BCR), wireless industry analyst Michael Finneran explores the discrepancies, and bridges the gaps. At long last we are actually starting to see some products edging toward true fixed-mobile convergence (FMC). FMC describes network services that integrate cellular and Wi-Fi/VoIP networks, offering the ability to hand off calls between the two environments. While we inch toward these capabilities, the buying population is still fundamentally confused about what's available and possible. I got a first-hand look at confusion generation at the recent VoiceCon Spring 2007 event in Orlando. Unlike many of my brethren in the analyst community who try to elicit straight answers from the well-prepared marketing types, I hit the show floor. I like to hear what kind of baloney the typical floor rat is being fed. Most of the time I hang back in the shadows and listen to the questions that are being asked and the answers being provided. FMC was the topic I was most tuned into, and while I won't say the answers I heard were outright lies, they did appear to demonstrate a wilful avoidance of the truth. As FMC solutions are now being described in the general business press, we can anticipate inquiries from our user populations. To respond to those requests, we must develop a way to categorize the solutions and a clear understanding of how they work. My favourite vendor description was an "automatic" handoff capability that required the user to press a button - that's "manual," as in the Latin manus, which means "hand!" Benefits of FMCUsers hope to reduce their cellular costs by shifting some calls to the WLAN. A significant and growing number of cellular calls are placed while in range of a PBX station, while more mobile professionals are using their cellphones as their primary business phones. The new etiquette of business is that we give our office number to everyone, but we give our cellphone number to the people we really want to hear from. Realizing those cost savings rests on the assumption that we actually can get those calls off the cellular network and onto the WLAN, and that our cellular charges will go down as a result. An automatic hand-off would ensure that the call transitions to the WLAN, but will that really reduce the bill? If our cellular contract is based on a bucket-of-minutes plan, we won't see any savings until the next contract renewal. Further, the cellular carrier will probably charge something for the hand-off service; the initial plans we're seeing in the US charge a flat monthly rate of $20 per handset per month.The focus on direct savings tends to mask the real benefits of FMC: accessibility and productivity. Far too much time is lost trying to reach people at critical times, which slows down decision making and corrective actions; those inefficiencies become critical in customer-facing operations. The responsible managers are often cloistered in meetings for a good part of the day. The period between meetings is typically dead time, but a WLAN voice capability could allow these individuals to check their voice mail and return calls while en route. The cellular carriers like to point out that their service can make those parties accessible. However, we all know that indoor cellular coverage is iffy unless we have arranged for an indoor repeater or distributed antenna system to address those coverage issues.Frankly, with our current FMC initiatives, we are aiming too low. We are struggling to provide seamless voice capability, but we should be including instant messaging, paging, email and data access in an overall solution. The migration to IP-PBX systems is bringing about the vision of unified communications, and we're stuck on the problem of handing off telephone calls. Will all of those rich UC applications be reduced to a phone call the moment someone walks out the office door? Developing an FMC lexicon The confusion that surrounds FMC stems from the fact that we don't have a standard set of terms to describe the various options available. The vendors' meandering descriptions are almost impossible to comprehend, and generally seek to avoid any mention of limitations. So once again it falls to the buyer to put the options into perspective and help users understand what can and can't be done. The solutions we have for FMC today can be grouped into three primary categories:Non-integratedCarrier-controlled: manual and automaticPBX-controlled: manual and automatic Non-Integrated: dual-mode handsets It may seem ironic that our first integration solution is not actually integrated, but instead simply contains both technologies, without providing the ability to move a call from one network to the other while the call is in progress. We're talking about dual-mode Wi-Fi/cellular handsets, and for some workers, this solution may be all that's needed. In fact, not every worker even needs dual mode Wi-Fi/cellular. Today, Wi-Fi-only voice devices are typically used by nurses, warehouse workers and retail clerks, who are not given company-provided cellphones. So a Wi-Fi only device like those from SpectraLink Corp., Vocera Communications, or Cisco Systems Inc. is all they need. But if the technology is going to extend to management and professional workers, we will have to provide handsets that include both Wi-Fi and cellular capability. It's unlikely that management and professional users will accept a solution that has them hauling around two separate handsets; Batman's utility belt might become the new management power-suit. The good news on the WLAN voice front is that better handsets are becoming available - at least for single mode. The new WLAN-only models from SpectraLink (8020 and 8030) and Cisco (7921) support the full range of required features including a/b/g radios, 802.11i/WPA2 encryption, and 802.11e/WMM QoS. Furthermore, better battery technology, coupled with new over-the-air tricks like Automatic Power Save Delivery (APSD), has doubled the battery life. The same cannot be said of the current crop of WLAN/cellular phones. A review of the 97 "Cellular Convergence" products listed on the Wi-Fi Alliance's website, including those from Nokia Corp., Samsung, Motorola Inc. and NEC Corp., found no devices with 802.11a radios and few with WPA2 encryption or WMM QOS. So while the cellphone makers are starting to put Wi-Fi on their handsets, they certainly haven't figured out the market requirements. And the big question will be whether the cellular carriers will offer the same level of subsidies on handsets that can make calls on networks other than their own. Carrier-controlled solutions True fixed/mobile convergence will require the active participation of the cellular carriers. The carriers will have to allow interconnection to their signalling networks so that calls can be transparently handed off in either direction (cellular-to-WLAN, WLAN-to-cellular). That type of transfer will have to address both the signalling and the actual call or "media" path. The configurations we are seeing today all depend on a VoIP network to provide the interface between the cellular and private networks. In T-Mobile USA Inc.'s FMC service, when a mobile user involved in a cellular call comes within range of the WLAN network, the dual-mode handset automatically sends a handoff request to the cellular carrier over the WLAN connection and through the IP network. If this were being done with an IP-PBX, a softswitch in the cellular network would engage a signalling exchange with the telephony server on the customer's IP-PBX to set up the VOIP connection and request a handoff from the mobile switching system, and the call would then be handed off from the base station network to the softswitch and on to the VOIP connection. The IP-PBX system would have to continuously monitor the availability of the WLAN voice user, and pass the call back to the cellular carrier if the user moves out of range of the WLAN. Conceptually, that's how the handoff process would work. Practically, the process could be controlled using Unlicensed Mobile Access (UMA) or IP Multimedia Subsystem (IMS). IMS could provide a richer set of features, but that doesn't matter because the carriers are not ready to provide it to enterprise customers in any event. While they cite concerns about maintaining call quality (as if the quality of cellphone calls is that great to begin with), their real issue seems to be customer control. The cellular carriers feel they have a unique franchise in providing mobile telephone service, so why screw around with a good thing? As long as they all take the same position, they feel they can dictate the rules of the game.Two cellular carriers have broken from the pack. T-Mobile introduced its consumer-oriented FMC solution, called Hot Spot @ Home, on a limited basis, using UMA technology. For the enterprise customer, Sprint/Nextel has gotten closest to the mark. At VoiceCon, the company was described an FMC solution called Wireless Integration. While the beta version of the service does not support automatic handoffs, it is the first time a cellular carrier has provided a link to its signalling network.PBX-controlled solutions As the carriers have been reluctant to open up their networks, the PBX/premises equipment suppliers have come up with methods to simulate that FMC functionality. The difference is that the PBX is now in control of the hand-off process. The handoff may be either automatic or user-initiated. Avaya Inc. and Motorola announced the first automatic transfer solution back in 2004 with their Seamless Convergence product. Besides the fact that it was neither "seamless" nor "converged," it did manage to transfer calls between a WLAN connection and a cellular connection.Only one handset model, the Motorola CN620, was supported. However, in the end, Cingular (now AT&T), the cellular "partner" in this adventure, refused to certify the CN620 handset for use on their network, and the product never made it to market. Start-up DiVitas Networks has now resurrected the idea, and sells a Mobility Controller that works like Motorola's wireless controller but can interface with a variety of PBX systems. DiVitas also provides a software package that allows a dual-mode handset to generate about a dozen PBX-type features. The product was launched in the first quarter this year, so we are waiting to see how it fares in the marketplace. In the meantime, some of the other IP-PBX vendors, including Avaya and Cisco, are opting for a simpler approach that relies on the user to initiate the handoff. This manual solution depends on a few elements. When an incoming call is received, the Simultaneous Ring feature rings the user's desk set or WLAN handset, and simultaneously calls the user's pre-stored cellular number. This function will work with any cell phone (i.e., a dual mode handset is not required), but if the user's PBX station were a WLAN phone, a dual mode WLAN/cellular handset would be preferred (so you don't have to carry two wireless phones). When the call is answered on either device, the ringing is stopped on the other device. If the user has answered the call on the PBX station and subsequently needs to leave the building, she can press a key on either the desk set or the wireless phone that causes the IP-PBX to call their cellular number and transfer the call to that connection. There's a reverse scenario if someone calls the user's business number and the IP-PBX forwards the call to the user's cellphone (i.e., if that's the device the user picked up first). If this user is in transit during the call, and reaches her desk while the call is still in progress, he or she can pick up the call on the PBX station and drop the cellular connection. Having the user initiate the transfer alleviates the need to have a controller that monitors the station's availability on the WLAN. Of course if the user is on a WLAN connection and they walk out of range before transferring the call to a cellular connection, the call will disconnect. Conclusion Functionality, transparency and the monetary impact of the different solutions will vary based on the configuration used. In PBX-controlled alternatives, we will be burning cellular minutes any time a call is extended to the user's cellular number. Of course, we still have the problem of indoor cellular coverage, and calls can only be transferred to the PBX station (wired or WLAN) if the PBX is in control of the call. If the user receives a call directly to their cellular number, the PBX is out of the loop. When it comes to pricing, both T-Mobile's Hot Spot @ Home and Sprint/Nextel's Wireless Integration are initially priced at $20 per user per month. If we are on a cents-per-minute cellular plan, we might be able to demonstrate a direct savings if we can cut $20 worth of cellular usage per month. However, we would do the organization a disservice if we focused solely on cost savings. Accessibility and productivity are what FMC is all about, and that's where the real organizational impact will be seen. We should be looking beyond simple voice calls to solutions that mobilize the entire user experience, including text messaging, paging, email and network access. And we'd better get a clear way to describe these capabilities, or the users won't have any idea what we're talking about. Michael Finneran is president of dBrn Associates, Inc., an independent consulting firm in Hewlett Neck NY, specializing in the design and installation of domestic and international networks. He is the instructor for BCR's data communications courses on "Wireless Networks For Voice And Data" and "Wireless LANs." This article is reprinted by permission of BCR.

Clearing up fixed-mobile confusion

News | June 21, 2007

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