Load-aware hand-offs in software defined wireless LANs

Abstract

In Wireless Local Area Networks (WLANs), providing seamless mobility and balancing load among Access Points (APs) are challenging issues due to simple signal strength based association and hand-off mechanisms employed at wireless clients. Extensions to Software Defined Networking (SDN) framework for wireless networks could help to address theses issues in an efficient and cost-effective manner with a central view of WLAN at the SDN controller. In this work, we propose a novel load-aware hand-off algorithm for SDN based WLAN systems which considers traffic load of APs in addition to received signal strength at wireless clients to solve load imbalance among APs and offer seamless mobility. We implemented the proposed algorithm on a small-scale prototype testbed and obtained improved network throughput for mobile clients as well as static clients compared to legacy hand-off algorithms used in WLANs.

Terminal handover in software-defined WLANs

“…To solve the above problems, many researchers have devoted themselves to researching SDN-based WLAN architecture and terminal handover methods [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Odin [15] enabled the seamless handover of terminals by performing virtual access point (VAP) migration.…”

Performance evaluation of SDN WLAN architecture

“…The key novelty is merging control channels under SDN management. The original Odin solution or its derivations [7], [11] use separated control channels for part of network running under 802.11 standards and the rest. These separated control channels are depicted in Fig.…”

“…The communication protocol between AP and SDN Controller is designed as extension of OpenFlow protocol following specification for extension design [11]. We divide functionality of the communication protocol to two main parts based on 802.11.…”

Software-Defined Wireless Networking Opportunities and Challenges for Internet-of-Things: A Review

“…The limitations of this work are: a) The association and disassociation processes do not count the load on APs, b) Odin runs over single controller hence it will be difficult to prioritise the multiple applications running over single controller. In [24] Odin's work was extended with the proposition of a novel load aware hand off scheduling algorithm running over SDN centralized controller for SDN based WLAN networks. In [25] the impact of OpenFlow SDN over wireless networks was evaluated, particularly in terms of end-to-end delay, throughput and jitter.…”