April 2001

BY RICHARD HAYTER

To succeed in this quickly evolving market, providers must be able to adapt their networks with flexible, scalable solutions. They walk a tightrope in planning how they will evolve their mesh or layered network architecture. Ever present is the knowledge that profits from long-distance are dwindling, and unfavorable economic news during the first quarter of 2001 has driven companies and individuals to scrutinize expenditures more closely than when the American economy was in high gear.

As carriers plan for this growth, it is critical that they consider the signaling capacity of their networks. As traffic loads in the network grow, and more messages are sent over signaling networks, one must note the crucial role that SS7 plays in providing call set up and tear down information and the intelligence it supplies to support roaming, number portability, instant messaging, caller identity, screening, and mobile Internet access. The dramatic subscriber growth and the addition of new data services threaten to exhaust the signaling capacity of many wireless networks.

Rather than expanding their legacy networks to increase their network capacity, many mobile carriers are making a technology leap. They are turning to IP transport to handle network expansion costs effectively. SS7 signaling over IP reduces transport costs, delivers flexible bandwidth, greater message throughput, and lower network infrastructure cost. It also lays the groundwork for the next-generation packet telephony network and positions carriers to deliver the 3G services that will keep them competitive in the marketplace.

SURGE IN MOBILE SIGNALING
Wireless calls are by nature signaling intensive and require five to seven times more signaling than a typical wireline call. As the base of wireless subscribers increases, so does signaling traffic. Dataquest projects that the number of mobile phone subscribers worldwide will hit the 818 million mark this year -- a 24 percent increase over the year 2000. A GSM operator in the UK added over 1.5 million net new customers in the last quarter 2000 alone. And, the industry has not yet reached a 20 percent penetration of the global market.

The addition of new services like SMS (short message service), E911, mobile commerce, and high-speed data access is further fueling the surge in signaling traffic. Additional growth is expected with the use of wireless application protocol (WAP) phones and the introduction of the new 3G services on the horizon. According to estimates by Cahners In-Stat Group, by the year 2004, over 51 percent of all mobile computing devices shipped will be wireless enabled.

MANAGING GROWTH
The PSTN was designed to carry one type of traffic -- voice. It is not well suited to efficiently handle dramatic increases in traffic loads and the delivery of new, data services. Signaling traffic in today's wireless network is packet-based. However, the transport of the signaling is based on the TDM network. As signaling traffic increases, the capacity of the TDM network must also be increased by the addition of switches and the point-to-point connections between the elements.

Many wireless carriers are looking to packet technology to solve the bottlenecks that bandwidth limitation is creating in their networks. Rather than deploying more and more circuit switches and signaling links with underutilized capacity, they are choosing to transport the signaling traffic over high-speed, packet backbones.

Packet switching, a data transmission technology, assembles data into distinct, digital bundles or packets. Each packet contains a header with source and destination addresses. Switches or routers in the network read the information and forward the packet to the appropriate destination without the need for a dedicated circuit, thus enabling packets from many different sources or media to be carried over the same pipe simultaneously. Connections are established on a packet-by-packet basis, and bandwidth is not allocated until it is actually needed. Unlike circuit-switched networks, no bandwidth is utilized when there is no information being transported.

MAINTAINING QoS
Essential to the integration of networks and services is the delivery of the same quality of service and reliability that consumers have come to expect from today's fixed PSTN. This translates to interoperability with existing networks; ubiquitous call completion; carrier-grade reliability and serviceability; integrated billing and customer care; and transparent delivery of services such as free phone calls, premium rate calls, calling cards, voice-messaging, and Internet call waiting This IP-enabled signaling architecture can help wireless carriers realize the benefits of combining voice and packet technologies. The reliability, scalability, and robustness of the PSTN, when coupled with the flexible bandwidth and rapid service delivery of the packet network, are essential elements to succeeding in today's rapidly evolving wireless market and tomorrow's 3G world.

Richard (Dick) Hayter is the assistant vice president of marketing for the Network Systems Division of Tekelec. Tekelec, a leading supplier of signaling and controls systems, develops innovative network switching and diagnostic solutions enabling the convergence of traditional and converged wireline, wireless, and IP voice and data communications networks. The company also provides products and solutions for call centers and other telecommunications markets. 

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