Research on Home NodeB Gateway load balancing mechanism

Home NodeB Gateway (HNB-GW) is a mobile operator's equipment through which Home NodeB (HNB) gets access to the core network. Without a Load Balancing (LB) mechanism, HNB-GWs' load distribution is determined by the random access of HNBs. HNB-GWs with too many HNBs may become overloaded easily. Once a HNB-GW is overloaded, other entering HNBs cannot be accepted and serviced due to the one-to-many relationship between HNB-GW and HNB in the traditional network architecture. To solve the problems above, this paper firstly brings a HNB-GW Pool concept to optimize the traditional architecture. Then in order to balance the load of HNB-GWs in the pool, this paper proposes two HNB-GW LB mechanisms, one is based on HNB-GW selection control and the other is based on periodic HNB migration. Through analysis in specific scenario, both mechanisms can effectively balance the load between HNB-GWs. LB mechanism based on HNB-GW selection control can select the best HNB-GW for a HNB when it needs to register, but its load adjust rate is relatively slow. LB mechanism based on periodic HNB migration is characterized by fast load adjust rate, but HNB migration may bring negative influence on the related HNBs, such as upper business interruption. Finally, a comprehensive solution which colligates the advantages of both mechanisms is brought forward.