Biblio

In 2008, 3GPP proposed the Long Term Evolution (LTE) in version 8. The standard is used in high-speed wireless communication standard for mobile terminal in telecommunication. It supports subscribers to access internet via specific base station after authentication. These authentication processes were defined in standard TS33.401 and TS33.102 by 3GPP. Authenticated processing standard inherits the authentication and key agreement protocol in RFC3310 and has been changed into authenticated scheme suitable for LTE. In the origin LTE authenticated scheme, subscribers need to transfer its International Mobile Subscriber Identity (IMSI) with plaintext. The IMSI might be intercepted and traced by fake stations. In this work, we propose a new scheme with a pseudo IMSI so that fake stations cannot get the real IMSI and trace the subscriber. The subscriber can keep anonymous and be confirmed by the base station for the legality. The pseudo identity is unlinkable to the subscriber. Not only does the proposed scheme enhance the security but also it just has some extra costs for signature generation and verification as compared to the original scheme.

Next generation cellular networks will provide users better experiences by densely deploying smaller cells, which results in more complicated interferences environment. In order to coordinate interference, power control for uplink is particularly challenging due to random locations of uplink transmitter and dense deployment. In this paper, we address the uplink fractional power control (FPC) optimization problem from network optimization perspective. The relations between FPC parameters and network KPIs (Key Performance Indicators) are investigated. Rather than considering any single KPI in conventional approaches, multi-KPI optimization problem is formulated and solved. By relaxing the discrete optimization problem to a continuous one, the gradients of multiple KPIs with respect to FPC parameters are derived. The gradient enables efficiently searching for optimized FPC parameters which is particularly desirable for dense deployment of large number of cells. Simulation results show that the proposed scheme greatly outperforms the traditional one, in terms of network mean load, call drop & block ratio, and convergence speed.