April 2002

BY RAVI RAVISHANKAR

One of the most fundamental ways in which people relate to the world and organize their lives is through their location. As societies become increasingly mobile, the ability to quickly and easily access location-sensitive information � how to get from one point to another, how to locate a service or business, how to locate another person � saves time and money and increases productivity. The ability to identify an individual�s location at any given point in time adds a whole new dimension to the kinds of services that can be delivered.

A Natural Fit
There is a natural synergy between the wireless market, packet communication technology, and location-based services (LBS). Wireless users are mobile by nature and quickly perceive the value of applications that make it easier for them to access information that simplifies their work and personal lives. Wireless devices such as handsets and PDAs already have the intelligence that can leverage communication and computing technologies to deliver value-added services. Add to this the rich location-specific content and applications that are available in the packet domain. LBS leverage the mobility of wireless technology, intelligent end devices, and the rich content of the Internet to deliver highly personalized services that can be customized to a user�s geographic location. Many new wireless devices such as in-vehicle tracking devices or wireless-enabled inventory tags can extend the usage of LBS to multiple vertical market segments beyond traditional person-to-person communication.

Wireless operators are hungry for new revenue-generating sources. As competition continues to heat up, the revenue per subscriber is declining. Mobile operators realize the tremendous potential for increasing their revenues and customer loyalty inherent in delivering the right service at the right location. And, technological and regulatory forces are at play, which are priming the market for the deployment of LBS.

The Technology�s In Place
The convergence of the Internet and wireless communications is driving technological advancements that are significantly impacting the mobile operator. Wireless carriers have been committing significant resources to upgrade their networks with packet technology to improve performance, reduce cost, and lay the groundwork for the evolution to 2.5G and 3G. The deployment of these next-gen networks enables the delivery of whole new class of services for which location will be a key attribute. Carriers view LBS as a way to create a steady revenue stream in the future by increasing air-time usage, speeding up market acceptance of the wireless Internet, improving customer satisfaction, and setting themselves apart from the competition.

The FCC�s E-911 mandate has boosted the opportunities for LBS in United States. The FCC has mandated that by year-end, every new handset must be enabled with Automatic Location Identification (ALI) technology such as Global Positioning Systems (GPS). By 2005, 95 percent of all wireless phones must be ALI enabled. The technology that carriers are required to implement to identify the subscriber�s location for public safety access points (PSAPs) is the same technology that will allow them to locate subscribers for the delivery of customized services.

Network Requirements
Two network technologies are required to enable LBS:

• Technology to identify the position of the wireless device in the network: Location can be determined through network signaling such as SS7 or with position determining equipment (PDE).
• Location Server (LS), also known as Mobile Position Center (MPC) in ANSI standards or Mobile Location Center (MLC) in GSM/UMTS related standards: LS will facilitate the accessibility of location information to outside applications, which require that location knowledge.

The easiest and least expensive means to position the mobile user is by leveraging the existing SS7 network. The SS7 message already contains information that identifies the cell sector in which the subscriber is located. The benefit of this solution is that the carriers already have SS7 networks in place and can utilize the existing technology to begin delivering services today. This method is less accurate than the PDE-based method since a cell sector may potentially cover a large area, but there are many applications that do not require extreme accuracy.

Position Determining Equipment
The PDEs can employ one of the three technology solutions for determining position � network-based, handset-based, or a hybrid of the two. There are pros and cons, which relate to the degree of location accuracy required, quality of service, and the cost of implementation associated with each solution. This technology is still maturing, which is perhaps the single biggest obstacle to deploying these services. Moreover, PDEs require hardware and software modifications to the network and/or the handset making it a more expensive solution. Requiring new handsets will also slow down the rate of market acceptance of new services.

Location Server
The LS is a database that administers the location information sent from the PDE or the signaling network. It requests location information, retrieves that information, stores it, and makes it available to other applications that request it. The LS is responsible for policy management regarding the privacy requirements of the subscriber, authenticating the applications authorized to access location information, maintaining an audit trail, and providing basis for charging. The LS, acting as a gateway from the wireless network to the applications that reside in other networks, must support a variety of conventional protocols as well as new packet protocols such as SIP and XML. Legacy services such as 911 require interfaces to PSAPs using extensions of legacy protocols. A standard interface is being developed by the Location Interoperability Forum (LIF) to define the interface between the LS and future applications.

Succeeding In LBS
LBS offer tremendous revenue opportunities to wireless carriers, mobile virtual network operators (MVNOs), and application service providers (ASPs). However, the issue of subscriber privacy could present a significant obstacle to market acceptance. The location of a device in the network is not the issue. It is the ability of unauthorized third parties to access the link between that location and a particular subscriber. If the subscribers are not in control of their location information, it is unlikely that that there will be a widespread market uptake. To maintain the user�s privacy and security, operators will have to physically separate the location information from the applications that use the position information. Future regulatory rulings related to subscriber safety, privacy, and law enforcement will likely have significant impact on the rollout of these services.

Mr. Ravi Ravishankar is director, Advanced Technology Planning, at Tekelec. His focus is on defining signaling solutions and products for the next-generation packet telephony and 3G wireless networks. Tekelec is a leading developer of telecommunications signaling infrastructure, softswitches, testing and diagnostic solutions, and service applications. Please visit their Web site at www.tekelec.com.

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