## 2 Background  
### Wireless Mesh Network (WMN)  
Most of the vendors' proprietary standards were implemented on the Open Systems Interconnection (OSI) layer 3, the network layer [13], with some implementations based on the Linux open802.11s project [8] working on the OSI layer 2 [10,11], the data link layer, because it was built in accordance with the IEEE 802.11s draft standard, while the remaining were implemented on the virtual layer between OSI layers 2 and 3, otherwise known as layer 2.5 [14]. One of the interesting implementations that work on the OSI layer 2.5 is the MIT Roofnet [14]. It is an experimental WMN setup with approximately 50 nodes that placed in apartments in Cambridge, MA, USA. This WMN was used to provide broadband internet access to the users in Cambridge. They used a small form factor computer with Roofnet software to manage the routing information of the WMN, and the best path was then chosen based on this routing information. In Roofnet, the routing protocol SrcRR was used to determine the high throughput paths. The ScrRR Routing protocol was based on Dynamic Source Routing (DSR) [15], and ScrRR uses the expected transmission count metric (ETX) to determine the best possible paths. The IEEE 802.11s protocol works on OSI layer 2. The Linux open802.11s project and the FreeBSD 802.11s implementation are the only few that follow the draft standard of the IEEE 802.11s. A test bed or prototype of WMN is required to evaluate the network performance of the implementation in a real physical environment. With the help of the test bed, the routing protocol or the routing metric can also be modified to further improve the IEEE 802.11s draft standard, and the resulting modifications can be observed and evaluated. [PERSON] _et al._[16] implemented their version of an IEEE 802.11-based WMN test bed on July 2007 by altering the existing Wireless Local Area Network (WLAN) functionality. They used Optimized Link State Routing (OLSR) [17] as the routing protocol, and they ran the system on ARM-based FALINUX EX-X5 + EXPCMCIA and x86-based laptop computers with Redhat Linux 9 and Fedora Core 4 distribution as the operating systems (OSs) respectively. Their implementation was tested with multimedia services using Gnomemeeting as the VoIP and video conferencing software and the workability was confirmed to be successful [16]. [PERSON] _et al._[18] fabricated another implementation of IEEE 802.11-based WMN test bed and published their research in 2010. In terms of hardware, PCEnglines ALIX 2C2, PCEngines WRAP IE and the Gateworks Cambria GW2358-4 were used in their implementation. Their system ran on an OpenWRT platform and was based on the Roofnet platform that works on OSI layer 2.5 which was explained earlier. In their implementation, they were able to perform simultaneous transmissions, and the intra-path interference was reduced due to the use of the non-overlapping channels. They developed the Interference and Traffic Aware Channel Assignment (ITACA) algorithm that considers the traffic condition and interference patterns for better channel assignment because their implementation used multiple radios per mesh point (MP). In 2009, [PERSON] _et al._[11] implemented a system that is based on the IEEE 802.11s draft standard. Their prototype was able to run in both of HWMP routing protocol's modes of operations, which are the proactive and reactive modes and the path selection based on the routing metric was evaluated. Laptop and desktop computers were used in their implementation along with Linux as the OS and C as the programming language of the software framework, and the Multiband Atheros Driver for Wi-Fi (MadWifi) [19] was used to create the wireless interfaces in the station, access points (APs) or WDSs.