AUTHENTICATION HANDOVER AND PRIVACY PROTECTION IN 5G HETNETS USING SOFTWARE-DEFINED NETWORKING
Recently, densified small cell deployment with overlay coverage through coexisting heterogeneous networks has emerged as a viable solution for 5G mobile networks. However, this multi-tier architecture along with stringent latency requirements in 5G brings new challenges in security provisioning due to the potential frequent handovers and authentications in 5G small cells and HetNets. In this article, we review related studies and introduce SDN into 5G as a platform to enable efficient authentication hand – over and privacy protection. Our objective is to simplify authentication handover by global management of 5G HetNets through sharing of userdependent security context information among related access points. We demonstrate that SDN-enabled security solutions are highly efficient through its centralized control capability, which is essential for delay-constrained 5G communications.
However, the specific key designed for handover and different handover procedures for various scenarios will increase handover complexity when applied to 5G HetNets. As the authentication server is often located remotely, the delay due to frequent enquiries between small cell APs and the authentication server for user verification may be up to hundreds of milliseconds, which is unacceptable for 5G communications. The authors of have proposed simplified hand – over authentication schemes involving direct authentication between UE and APs based on public cryptography. These schemes realize mutual authentication and key agreements with new networks through a three-way handshake without contacting any third party, like an authentication, authorization, and accounting (AAA) server. Although the handover authentication procedure is simplified, computation cost and delay are increased due to the overhead for exchanging more cryptographic messages through a wireless interface. For the same reason, carrying a digital signature is secure but not efficient for dynamic 5G wireless communications.
Over the past few years, anywhere, anytime wireless connectivity has gradually become a reality and has resulted in remarkably increased mobile traffic. Mobile data traffic from prevailing smart terminals, multimedia-intensive social applications, video streaming, and cloud services is predicted to grow at a compound annual growth rate of 61 percent before 2018, and is expected to outgrow the capabilities of the current fourth generation (4G) and Long Term Evolution (LTE) infrastructure by 2020 . This explosive growth of data traffic and shortage of spectrum have necessitated intensive research and development efforts on 5G mobile networks. However, the relatively narrow usable frequency bands between several hundred megahertz and a few gigahertzes have been almost fully occupied by a variety of licensed or unlicensed networks, including 2G, 3G, LTE, LTE-Advanced (LTEA), and Wi-Fi. Although dynamic spectrum allocation could provide some improvement, the only way to find enough new bandwidth for 5G is to explore idle spectrum in the millimeterwave range of 30~300 GHz.