Extended X2AP to support Distributed Load Balancing

Signaling interaction is necessary for the implementation of the Distributed Load Balancing (DLB) use case in LTE. The authors investigate typical DLB solutions´ requirements for X2 application protocol (X2AP). This paper presents a general DLB procedure which contains three sub-procedures: “reporting”, “balancing”, and “adapting”. But X2AP can only support the “reporting” sub-procedure, ignoring that the other two sub-procedures also need signaling interaction. Giving consideration to the scalability of interfaces, the authors design an extended X2AP in order to better support the various DLB solutions, including the function classification, the definition of messages and the relevant date types. Finally, based on the extended X2AP, the signaling interaction of distributed load negotiation mechanism is introduced into LTE and analyzed.