Coexistence of S-Band radar and 4G mobile networks

Today´s wireless network and radar systems are designed to obey a fixed spectrum assignment policy regulated by the Federal Communications Commission (FCC). The assignment served well in the past, but sparse or medium utilization of some frequencies confronts heavy usage of others. This ineffective spectrum allocation contradicts the dramatically increasing need of bandwidth for security systems like radar or mobile networks and causes the evolution of intelligent radios applying dynamic spectrum access i.e. cognitive radio. To underline the demand of dynamic spectrum allocation, this paper addresses coexistence between S-Band Air Traffic Control (ATC) radar systems and LTE mobiles operating in E-UTRA Band 7. Technical requirements for radar and mobile devices operating close to each other are addressed and coexistence validated by test and measurement performed at a major german airport. It is shown that throughput reduction, increased Block Error Rate (BLER) of these mobile radios and reduction of the probability of detection P_d of security relevant S-Band radar occur in the presence of the other service.