Business and Technology Implications

With the rise in Location Based Services (LBS) applications and the need to meet E911 requirements, the number of mobile cellular devices supporting Assisted GPS (A-GPS) is steadily growing. As one of the enabling LBS technologies, A-GPS offers customers higher position accuracy, quicker location fixes, and improved coverage of service in difficult locations, such as urban and in-building environments. As a result, mobile operators and device manufactures are looking for testing choices that quantify and benchmark real-world device performance.

Until recently, all industry-defined A-GPS test methodologies focused on testing the performance of a device over a cabled RF connection, bypassing the GPS antenna and associated circuitry, as shown in Figure 1. This approach does not give the complete picture of real-world device performance and its impact on the end-user experience of LBS applications. To achieve this, GPS performance testing needs to include all relevant components. An Over-The-Air (OTA) test methodology, shown in Figure 2, is the best solution to address this need.

This white paper presents an overview of the business and technology drivers for OTA A-GPS testing, which describes a method to satisfy the radiated testing requirements of all involved parties. While the white paper is intended for Department Managers, Lab and R&D Managers, and Engineers already working with A-GPS or OTA, the introductory content in the following sections is also beneficial for those unfamiliar with these concepts.