Efficient mm Wave Link Establishment and Maintaining Using Wi- Fi/mm Wave Interworking

Millimeter wave (mmWave) communication is considered as a promising candidate for the access link of the next 5G cellular networks. However, directional transmission via narrow beams must be used to mitigate the severe isotropic losses in this band. Hence, establishing and maintaining the mm Wave link especially in dynamic environments (i.e. under user mobility) turns to be a big challenge. Where, each deployed mm Wave access point (AP) in the target environment needs to perform an intensive and frequent beamforming training (BT) to track the channel of a moving user to preserve the link. This huge training overhead significantly deteriorates the system performance. This paper proposes a novel location-based BT scheme for mmWave link establishment and maintaining based on an interworking between mmWave and Wi-Fi bands. Where, an accurate UE positioning supported by the legacy Wi-Fi APs is used for reducing mmWave BT complexity and enables the network to fast explore the channel quality of the surrounding APs. Thus, a rapid path switching in case of the link quality degradation can be done. Simulations show that the proposed scheme provides a robust mmWave communication links with higher throughput and energy efficiency than the conventional scheme with the great overhead exhaustive BT protocol.