SOFTWARE DEFINED WIRELESS MESH NETWORKS: FROM THEORY TO PRACTICE A Thesis by Pinyarash Pinyoanuntapong Bachelor of Science, Wichita State University, 2016 Submitted to the Department of Electrical Engineering and Computer Science and the faculty of the Graduate School of Wichita State University in partial fulfillment of the requirements for the degree of Master of Science December 2017 © Copyright 2017 by Pinyarash Pinyoanuntapong All Rights Reserved SOFTWARE DEFINED WIRELESS MESH NETWORKS: FROM THEORY TO PRACTICE The following faculty members have examined the final copy of this thesis for form and content, and recommend that it be accepted in partial fulfillment of the requirement for the degree of Master of Science with a major in Computer Networking. Pu Wang, Committee Chair Chengzong Pang, Committee Member Jibo He, Committee Member iii ACKNOWLEDGEMENTS I would like to thank my thesis advisor Dr. Pu Wang of the EECS Department at Wichita State University. Dr. Wang was always available whenever I had a question about my research or ran into trouble. He continuously encouraged me to do the work on my own, but guided me in the right direction whenever I needed and motivated me to pursue PhD degree. I would also like to acknowledge the committee members: Dr. Chengzong Pang and Dr. Jibo He as the second reader of this thesis, and I am gratefully indebted for their very valuable comments on this thesis. I would also like to thank my lab members for their continuous support in validating my results all the time. Finally, I must express my very profound gratitude to my parents for providing me with unfailing support and continuous encouragement throughout my years of study and through the process of reaching and writing this thesis. This accomplishment would not have been possible without them. iv ABSTRACT Wireless mesh network (WMN) integrating with Software Defined Network (SDN) has been considered as a remarkable technology in the communication field since it has the potential to provide Internet broadband access with economical infrastructure. In par- ticular, this thesis demonstrates an experimental deployment of Software Defined Wireless Mesh Network(SD-WMN) equipped with multi radio(MR), multi channel(MC) { SoftMesh testbed. There are three major challenges that need be addressed in current multi-radio wire- less mesh networks. Due to the limited number of channels in IEEE 802.11 a,b,g,n, there will be tremendous interference in the network. Therefore, using multiple-channels with an effective channel assignment algorithm is imperative to decrease network interference. Second, when using multi links wtih different bandwidth for data transmission, assigning appropriate weight for each link is required to minimize the total transmission delay. Lastly, traditional Multi-path load-balancing in wired network cannot be directly implemented in WMN. Therefore, a proper load-balancing and widest path routing scheme is introduced to improve the overall network capacity. A performance experimental is presented to assess the effectiveness of our proposed algorithm. SoftMesh { wireless mesh network testbed is deployed in the Jabara Hall building at the Wichita State University. v TABLE OF CONTENTS Chapter Page 1 INTRODUCTION . 1 1.1 Wireless Mesh Network . 1 1.2 SDN . 2 1.3 Wireless SDN . 3 1.4 Research Objectives and Solutions . 3 1.5 Organizations of Thesis . 4 2 SOFTWARE DEFINED NETWORKING - A WIRELESS NETWORKING AP- PROACH ........................................ 5 2.1 Data Plane . 5 2.2 Control Plane . 6 2.3 Management Plane . 6 2.3.1 Core Functions . 6 2.3.2 Core Services . 8 2.3.3 Northbound API . 9 2.3.4 Southbound API . 9 2.3.5 Wireless Network Hypervisor . 9 2.4 Challenges . 10 3 MULTI RADIO MULTI CHANNEL WMN . 12 3.1 Chanel Assignment . 14 3.2 Dynamic Load-balance scheme for multi-channels(links) . 19 3.3 Multi path multi radio . 23 vi TABLE OF CONTENTS (continued) Chapter Page 4 TESTBED EVALUATION AND RESULTS . 26 4.1 Testbed Evaluation of Adaptive Weight Assignment . 26 4.2 Simulation of Multipath Multi Radio Routing scheme . 29 5 CONCLUSION AND FUTURE WORK . 35 REFERENCES . 36 vii LIST OF TABLES Table Page 4.1 Throughput (Mbps) of single channel and aggregate channel for 10 seconds . 26 4.2 Single Channel Transmission Delay . 28 4.3 Two Channels Transmission Delay . 28 4.4 Time series throughput of single path and multipath for 10 seconds (Mbps) . 32 4.5 Single Path Transmission Delay . 33 4.6 Multipath Transmission Delay . 33 viii LIST OF FIGURES Figure Page 2.1 SoftMesh architecture . 5 3.1 Virtual Wireless Mesh Backbone with multi-channel . 12 3.2 Co-Channel Interference . 15 3.3 Self-Interference . 16 3.4 Multi-Channel VBB with Channel Assignment . 18 3.5 Unbalanced Channel Bandwidth. 20 3.6 Virtual link. 24 4.1 Small scale testbed for adaptive assignment. 27 4.2 Time series throughput of single channel and aggregate channel . 28 4.3 Transmission delay of two channels compare to one channel . 29 4.4 Topology before apply widest path . 30 4.5 Best two paths based on widest path algorithm . 31 4.6 Throughput of multipath compare to single path . 32 4.7 Transmission Delay of Multipath compare to single path . 33 ix CHAPTER 1 INTRODUCTION In the wireless networking and communications field, two promising technologies that become an outstanding topics in research sector are wireless mesh network and software defined networking [1{5]. WMN is a network which consists of wireless nodes connected in a mesh topology. It is a rich interconnection of mesh clients, mesh routers and gateways. Wireless mesh architecture offers multiple redundant communication paths in the network. In todays world, software defined networking(SDN) is driving the networking field. The main advantages of SDN includes centralized control, centralized network provisioning, low operating costs, hardware savings and cloud abstraction. SDN concept is now majorly implemented in wired infrastructure. The idea of deploying SDN concept in the field of wireless networking is still in its initial stages. By incorporating the ideas of SDN along with WMN, a wireless mesh testbed is deployed in 2nd floor Jabara hall. It is being managed by a centralized controller to program the wireless routers. The testbed environment is composed of two kinds of traffic, the Control plane Traffic and the Data plane Traffic. Each type of traffic has a separate network of their own. Both networks share the same physical wireless infrastructure but they work independently (without interfering one another). 1.1 Wireless Mesh Network A WMN is made up of dedicated wireless nodes called mesh routers, which are config- ured using 802.11 wireless technologies. In a mesh network, mesh routers collect information from local mesh clients and relay this information to Internet gateways or to other nodes depending on the location of the destination host/server. Traffic within the mesh stays in- side the mesh, whereas traffic outside the mesh must pass through Internet gateway. All this makes the networking infrastructure decentralized and simplified because 1) each node need only transmit as far as the next node 2) each node transmits the data from not only 1 the host connected to itself but also from host connected to any other node in the mesh network. The design of WMN has an objective of making the network that is self-healing, self-forming and manages itself with minimal influence of a network administrator. In Soft- Mesh, the testbed uses 802.11S protocol to maintain the mesh connectivity in the network. Wireless routers in mesh network have several modes of operation. Access Point (AP): This is the most common mode that routers operate on. The router acts as a central connection point for the network, this allows wireless clients to connect to the network. Monitor mode: Monitor mode is a passive-only mode, no packets are transmitted. All the packets in the mesh are handed over to the mesh router completely unfiltered. This mode is useful to see what's going on the network. Mesh mode: This mode allows routers to communicate on a peer-to-peer basis. Mesh interfaces are used to allow multiple devices to communicate with each other by establishing link between multiple routers dynamically. 1.2 SDN Software Defined Networking is a new approach in computer networking where the traditional control plane and data plane residing in one hardware are decoupled. The de- coupling of control plane from the hardware reduces the overhead on the switches and they can function more efficiently. SDN typically refers to the following components. Control Plane: It is the brain of the SDN. It analyses the traffic from the switches and programs the switches to forward the data. Openflow is one of the standard languages used for commu- nication between the control plane and data plane. There are many open source controllers for example ONOS, RYU, Floodlight etc. We are using RYU controller in SoftMesh. Data Plane/ Infrastructure layer: It generally includes the hardware responsible for forwarding the data. The decisions are made by controller and it installs rules in the hardware. Whenever a packet comes to the hardware it checks the rule and forwards the data accordingly. We are using Openvswitch enabled wireless devices as the wireless mesh routers. Application Layer: In this layer, various business applications are developed using the APIs provided by the controller. For example GUI, security apps, traffic engineering apps etc. In general, 2 these apps are developed to be in sync with other apps. For example, GUI app is centralized app which will coordinate security and traffic engineering functionalities. 1.3 Wireless SDN WMNs are difficult to manage and upgrade because configurations are made manu- ally and are error-prone. It normally takes weeks or even months to provide new services for service activation, test, and assurance.