Their technology now proven, it’s time to get into details.

Since Sprint announced its intentions to deploy Mobile WiMAX nearly one year ago, the industry has come a long way. Sprint’s decision was followed by a wave of other WiMAX deployment announcements—both big and small, domestic and international. So WiMAX is definitely here; now the only question that remains is what exactly will the WiMAX network look like?

Consequently, at NXTcomm vendors aren’t so much focused on base stations and throughputs. Rather, they’re focusing on applications and logistics. What kind of services can a carrier run over a WiMAX network and how to backhaul and manage the gobs of IP traffic those applications will generate are two of the larger questions vendors are hoping to answer at the show.

Voice over IP (VoIP) is taking center stage as the IP telephony industry latches onto WiMAX as the next broadband medium for delivering packet voice. Several packet technology vendors will be targeting WiMAX this year at NXTcomm. The vendors see a definite market opportunity that hasn’t been highlighted very much in the wake of Sprint hype. Sprint is deploying a Mobile WiMAX network as a wide-area pervasive data network and has a massive investment in its CDMA infrastructure to serve its mobile voice needs. But almost any operator that doesn’t have the same cellular advantages definitely has VoIP high on the priority list, said Maniam Palanivelu, senior manager of WiMAX global product marketing for Nortel Networks.

“Data is a fundamental baseline of WiMAX, but we’ve found if you just offer broadband data, you’re not offering a sticky enough solution,” Palanivelu said. “There’s not a single customer that says ‘I just want to do data.’”

On that note, Nortel will be commercially launching the Communication Server 1500 VoIP softswitch at NXTcomm. While it is not specifically for WiMAX networks, it is a scaled-down version of its CS 2000 switch geared at small and medium-sized carriers, making it an optimal choice for WiMAX deployments, Palanivelu said. Nortel expects operators to start announcing complete core-to-radio deals as the year goes on as many smaller operators—and some big ones, too—conclude their trials and move from soft launches into full commercial launches. Some of those operators will likely be wireline players looking to expand in wireless, bridging it with their wireline VoIP services, Palanivelu said.

“That’s where our experience comes in,” he said. “We are no strangers to voice over IP.”

Even switch vendors with no traditional relationship to the wireless network see WiMAX as an entry point into mobile. “From our perspective, WiMAX looks suspiciously like other IP deployments,” said Dan Marcus, director of marketing for MetaSwitch. “WiMAX is just another access network, but it’s a compelling one because it allows us to move fairly quickly to fixed/mobile convergence.”

MetaSwitch has partnered with SOMA Networks to deliver a complete core-to-customer premise solution for rural operators. SOMA has already built session initiation protocol user Agent functionality into its modems, making SOMA gear ready for VoIP services out of the box. Currently, the combined solution is in trials with two rural operators. In addition, the companies’ switching and access gear have received Rural Utilities Service classification from the U.S. Department of Agriculture, meaning rural operators can use federally subsidized loan funds to purchase their equipment.

“We’re at the front end of this market,” Marcus said. “We’re offering a very real solution. We can go to customers and tell them, ‘We’ve already tried this; it’s not an abstraction.’”

While VoIP will be a big focus at NXTcomm, the big spike in wireless data usage WiMAX is supposed to deliver also will be highlighted. Transport and aggregation technology vendors are now focusing more on the wireless market as data capacities are increasing, requiring the backhaul capabilities of individual cell sites to scale accordingly. WiMAX is expected to exacerbate the backhaul issue with its data-centric focus.

Most of the 2G and 3G cell sites in the U.S. are backhauled via bonded T-1 lines. Yet merely connecting more copper won’t keep up with the increased average data loads as EV-DO and UMTS are rolled out in the U.S., carriers are shifting to fiber, said Jim Orr, principle network architect for Fujitsu in North America. In the last year, towers backhauled with fiber jumped from 6% to 10%. 3G networks will continue to drive fiber to the base station, but WiMAX rollouts will quicken the pace further, Orr said.

A WiMAX cell site can put 10 Mb/s to 20 Mb/s of usable throughput on the network, Orr said. While T-1s are attractive because they're a lot cheaper, costing $100 to $150 per month, the number of bonded T-1s necessary to meet those capacity needs start adding up. “Fiber is already attractive to carriers, but WiMAX is going to drive it home,” Orr said.

Fujitsu already provides a good deal of Sonet fiber infrastructure in the country, and many of its customers such as AT&T and Verizon are looking to build out their metro area networks. But they are also building fiber access infrastructure, Orr said. Verizon’s wireless FiOS build-out follows the same footprint as Verizon Wireless’s mobile footprint. Those fiber builds could be used just as easily to backhaul cellular base stations as well as WiMAX, Orr said. The dynamics of tower siting are changing for that reasons.

“Ten years ago, it wasn’t the major criteria for placement, but today location in relation to fiber is a major component in tower placement,” Orr said.
Fiber isn’t the only backhaul technology vendors will be promoting at NXTcomm. Point-to-point broadband wireless firm Ceragon Networks is positioning its wireless Ethernet solution for the backhaul market in the U.S. In Europe, wireless is the primary backhaul option because of the high cost of leased line access. U.S. carriers so far haven’t encountered this problem because of the competitive landscape. But because of copper’s inability to keep up with the more robust data requirements of WiMAX, Ceragon now sees an opportunity to sell its Ethernet backhaul gear to WiMAX
operators, said Ran Avital, director of strategic and product marketing for Ceragon.

Those increased data demands are also drawing the attention of edge data aggregators. Redback Networks, which is now a subsidiary of Ericsson, sees WiMAX as a key jumping point into wireless networks for its SmartEdge multiservice routers. Redback will be showing off its new SmartEdge 1200 router, which Redback officials say is designed to bridge both wireless and wireline networks as part of new owner Ericsson’s “full service broadband” strategy.

Current wireless networks depend on gateways to off-load and route data traffic, the Gateway GPRS service node (GGSN) for GSM/UMTS networks, the packet data serving node for CDMA networks and the access service networks (ASN) gateway for WiMAX networks. Those gateways, however, were optimized for networks that saw far greater voice traffic, not packet data, said Arpit Joshipura, vice president of product management
for Redback. As wireless networks start to resemble broadband wireline networks more, those aggregating platforms won’t be enough to handle the quantity of packets flowing through them, Joshipura said.

“Traffic is going up—the ASN and GGSN are getting hammered,” Joshipura said. “It’s not just the sheer amount of traffic either. It’s the different type of traffic, all of
which those carriers have to handle according to their service level agreements.”

While Redback is aiming its SmartEdge routers at 3G carriers, WiMAX will be the access technology to truly test the need for a multiaccess, multiservice router on the wireless network edge. WiMAX will be all data, a flat-IP network that packetizes everything from voice, data to Internet access. While Redback is at first placing the SmartEdge 1200 behind the ASN, where it can handle session control, aggregation and routing of voice, video and data, Joshipura said Redback hopes to convince service providers to discard the ASN completely. Instead its functions will be added to the SmartEdge solution as software, he said, creating a seamless link between the base station and router without a potential ASN bottleneck in between.

“We created our architecture this way specifically for that reason,” Joshipura said. “We saw the demand for it in wireline, and we’re able to dominate that space. Wireless is only a few years way from that same point.”

Though the WiMAX focus of NXTcomm may be on applications and peripheral equipment, it doesn’t mean the access equipment vendors won’t be there in full force. All of them, however, have already unveiled their 2.5 GHz base stations targeting the U.S. market, and now they’re looking to rack up customers. Motorola, Nokia and Nortel will have their demos revved up for the show. Nokia will even be retrofitting its Internet tablet N770 Wi-Fi devices with WiMAX radios so it can show conceptually the Mobile WiMAX experience for the end user on a hand-held.