PRS Selection Guide

Model	Reference Source	Antenna Type	Telecom Outputs	Equipment Costs	Install Complexity	Main Applications
Primary Reference Clock (TimeSource and TimeCesium)	GPS and Cesium	Window, Wall, Roof Top, None	4 T1/E1	High	Medium	International Gateways Tandem Offices Offices serving important public safety facilities
TimeCesium	Cesium	None	2 T1/E1	High	Very Low	SONET/SDH Hubs and ADMs Class 5/End offices Offices with limited or no sky view GPS diversity
TimeSource 3000 (T1) TimeSource 3100 (E1)	GPS	Roof Top	2 T1/E1 + (8 T1/E1)	Very Low	High	SONET/SDH Hubs and ADMs Class 5/End offices Offices with simple roof access
TimeSource 3500 (T1) TimeSource 3100 (E1)	GPS	Window, Wall, Roof Top, None	2 T1/E1 + (8 T1/E1)	Medium	Low to Medium	SONET/SDH Hubs and ADMs Class 5/End offices Offices with simple window/wall access
TimeProvider 1500	IEEE 1588 PTP	None	2 T1/E1	Low	Low	Offices with limited or no sky view Co-location offices Carrier Ethernet-fed offices