WIRELESS: Carriers look to IP for back haul

NEW ORLEANS — Nokia is looking beyond the craze for High-Speed Downlink Packet Access (HSDPA) and its uplink equivalent, HSUPA, to argue for a symmetrical broadband Internet Protocol network that will push Layer 3 IP protocols out to base transceiver platforms.

At the recent CTIA Wireless show here, the company introduced Internet-HSPA, which will be based on an intelligent services node that unifies IP services for a variety of traffic types in digital cellular networks. In theory, this could eliminate radio network controllers and signaling gateways within a wireless net, said Eric Updyke, vice president of strategic planning and marketing at Nokia Networks North America.

"We hear a lot about the reduction in capex because of elimination of network nodes, and we hear a lot about the overall reduction in opex from a unified IP, since it simplifies traffic," said Updyke. "What's becoming more clear is that moving to IP also allows the flattening of the network."

Updyke said HSDPA and HSUPA are driving getting carriers to implement long-delayed increases in bandwidth in their networks. But WiMax and 802.20 technologies on the horizon are spurring carriers to make their networks as IP-centric as possible, as well as to move to higher bandwidth in the core.

The shift of wireless carrier services from circuit switching to Internet Protocol is driving backbone and RF back-haul transport to IP. Such a conversion has been anticipated since the debut of 2.5G data services in the mid-1990s, but it finally appears to be happening in order to handle the flood of high-speed data services carriers are rolling out this year and next.

"It is still a big mental shift for carriers, who are used to thinking in terms of T1 and T3," said Bruce Blain, vice president of sales for digital microwave at NEC America Inc.'s radio communications systems division. "But we will be making the switch to IP back haul in both our high-end and low- to midrange back-haul radios."

The message is similar whether back haul is based on microwave-frequency radios; higher-frequency, 30- to 50-GHz systems; or fiber optics. And what is good for point-to-point links appears justifiable for transport and aggregation networks as well.

The IP stampede is driving a re-design of several wireless-system nodes for digital cross-connect and aggregation. For example, Eastern Research Inc. (Moorestown, N.J.) has sold a popular 1U access gateway based on T1/

T3 transport for three years. In 2003, the company bought Avail Networks Inc. (Ann Arbor, Mich.) and added Avail chip-level hardware for IP and ATM switching to its existing 1U access platform. At CTIA, Eastern introduced the BSG-1U for offering any-service/any-port combinations of TDM, ATM and IP for wireless aggregation.

Dave Kamm, director of marketing for Eastern Research, said the new architecture not only would fit the Nokia model of IP end-to-end in the network but can also take the place of existing back haul in point-to-point rural areas. TDM service will remain an important line of business indefinitely, Kamm said, but "more carriers of medium and smaller size are moving the bulk of their networks to IP, sooner rather than later."

James Teel, senior director of 3G product management at UTStarcom Inc., described a vision of cellular backbones based on IP that looked surprisingly like Nokia's I-HSPA concept. UTStarcom entered the wireless-switching-infrastructure market in China with the mSwitch IP soft-switch architecture, used for the iPAS network. Today that platform constitutes the basis of the three-pronged MovingMedia family: the MM-

2000, for cdma2000; MM6000, for time-division CDMA; and MM8000, for wideband CDMA.

Teel said that UTStarcom's "commitment to IP from day one makes us unafraid of flattening and collapsing of the backbone network."

UTStarcom's cdma2000 system is based in part on the company's acquisition of Telos Technology and CommWorks. For its TD-CDMA basestation, UTStarcom licensed ASIC technology and firmware from IP Wireless Inc. The China-based company has played the longest in W-CDMA, where it has offered a full-featured basestation since 1998.

For the time being, the three networks must be addressed by three products, all moving to IP backbone services, although Teel said that UTStarcom is talking to small companies with programmable software-defined basestation architectures, such as Vanu Networks.

The new strategies in back haul are sparking a renaissance in back-haul management concepts for the first time in nearly a decade. For example, a venture-backed startup in San Francisco, FiberTower Inc., made its debut at CTIA, showing a network management system and managed services to link digital microwave back haul with fiber transport offered by specialized fiber carriers.

Chief operating officer Keith Kaczmarek said FiberTower has received funding from multiple tower specialists in the industry. He said the company is discussing deployment deals with several microwave back-haul radio companies.

Both groups of companies consider FiberTower more of an enabler than a competitor, Kaczmarek said.

Operation centers

Besides providing provisioning software that is a modified version of a commercial tool, FiberTower manages network operation centers in California and Pennsylvania which serve as aggregators between multiple back haul radios and fiber transport that is leased from a fiber carrier.

"Our aggregation eliminates the weakest link in the back-haul network: the copper-based T1 line," Kaczmarek said. "Today, customers still ask for TDM service because of sits familiarity, but we are prepared for an all-IP back-haul network in the near future."

Optimizing network traffic for back haul is the basis for a new business entity within NMS Communications Inc., the Framingham, Mass., embedded-telephony company. R. Brough Turner, senior vice president of technology at NMS, said the AccessGate back-haul software is one of two businesses launched by NMS that are being treated as virtual standalone entities. The other, Mobile Place, was launched at CTIA as a subscriber management software environment for mobile services.

Dan Daly, NMS vice president of network infrastructure and general manager of AccessGate, said the company had to appeal to the "low-hanging fruit" where back-haul traffic management was most critical, such as in satellite-based back haul. Now, he said, the arrival of ubiquitous 3G, experimental 4G and integrated broadband wireless services is pushing the move toward an all-IP network.

"The T1s and T3s are never going to be turned off, but wireless carrier networks are finally starting to experience bandwidth pain points," Daly said. "Ad we're expecting a significant evolution of back-haul networks in the near future."