Trimble has announced that Grayson Wireless has selected Trimble’s Global Positioning System (GPS) time and frequency receivers for installation in Grayson’s Geometrix® wireless 911 caller location systems. As a part of the Geometrix system, Trimble’s GPS receivers will provide precise timing synchronization between Geometrix base station location receivers to locate an emergency caller’s handset.
Grayson’s network-based Geometrix Wireless Location Systems are compatible with all cellular and PCS network technologies, and all existing customer handsets. Grayson builds and installs Geometrix systems for wireless carriers to comply with the Federal Communication Commission’s (FCC) Phase II E911 regulations for wireless 911 caller location. The system automatically determines and forwards a wireless caller’s location coordinates to public safety agencies that receive emergency calls. To maintain caller privacy, Geometrix systems are designed to provide location information only when a wireless user initiates a 911 call.
Although the number of 911 calls from wireless phones exceed 100,000 per day in the U.S., location information for a wireless caller is not available to the emergency response agencies. Instead, 911 dispatchers must rely on information given by the mobile caller who, because of injury or unfamiliarity with his/her surroundings, often cannot provide accurate location information. This can delay or prevent assistance to the emergency. To address this problem, the FCC has mandated that wireless carriers must install location systems able to locate the majority of 911 emergency callers within 100 meters.
Grayson’s Geometrix system can locate wireless 911 callers within the FCC’s new accuracy requirements. The system makes precise measurements of a wireless caller’s signals at special Geometrix signal sensors installed at multiple base station (cell) sites in wireless carrier networks. Grayson’s system uses the very small differences in the caller’s signal arrival times at the multiple receiving sites to calculate a caller’s location. The signal timing measurements require great accuracy and close synchronization among the Geometrix sensors. To do this, Grayson is installing Trimble’s GPS receivers in Geometrix wireless location sensors to supply timing and synchronization to within 100 nanoseconds or better.