**Acknowledgement**

Authors would like to acknowledge the CSIR Meraka for financial support, Ishmael Makitla for the HPN diagram and the INTECH Book Publishing Editor for considering the chapter proposal for submission.

#### **7. References**

174 Wireless Mesh Networks – Efficient Link Scheduling, Channel Assignment and Network Planning Strategies

proposed by Kyasanur and Vaidya (2005).

**6. Conclusion and future work** 

ing the power settings of the transmitter.

**Author details** 

**Acknowledgement** 

proposal for submission.

*CSIR Meraka Institute, South Africa* 

could also be applied to other rural deployments as well.

Thomas Olwal, Moshe Masonta, Fisseha Mekuria and Kobus Roux

conventional analytical results of Kyasanur and Vaidya (2005) was compared with the HPNs of the BB4allTM architecture. Data from Table 5 shows that HPNs of the latter with special radios and antenna arrangements is more superior to the HPNs with standard antenna gains. While all cases considered dual radio dual channel specifications, the HPNs of the BB4allTM architecture have higher throughput antenna configurations than the work

The BB4allTM architecture makes use of omni-directional antennas to maintain mesh connectivity, while directional antennas support information relay over long distances with high power gains. It was found that the impact of multipath and MIMO of IEEE 802.11a/n air interfaces on achievable capacity can be characterized by OFDM modulation scheme, antenna configurations, and multiple streaming of frames or packets. Both the analytical and numerical results showed that the higher the dimensions of these parameters, the higher the achievable capacity due to benefits derived from channel diversity. It was also confirmed based on related previous works that increasing the number of interfaces per HPN and channels in the network does increase the achievable E2E capacity in any arbitral network placement. One of the contribution of this study was the innovation constructed to improve performance of the commercially available WLAN devices. The pillar of innovation was that increasing the antenna gains could improve capacity of real networks even without increas-

The CSIR Meraka Institute, South Africa, through living lab initiatives, are currently gathering field data regarding end-to-end capacity that is experienced by rural community Internet users. The findings will be assessed with a view of considering possible improvements of future network architectures that can provide high data rates. Other possible exploration of increasing capacity of community networks (i.e., Peebles valley mesh in South Africa) include utilization of unused frequency (TV white space) spectrum. The TV white spaces spectrum fosters high capacity signal transmissions over long distances in rural terrains. Thus, cognitive and foraging radio techniques are promising tools toward spectrum and energy efficient network management for the next billion internet users. It should also be noted that, although the theoretical derivations were applied to the PVM network, they

Authors would like to acknowledge the CSIR Meraka for financial support, Ishmael Makitla for the HPN diagram and the INTECH Book Publishing Editor for considering the chapter


Berthilson, L. & Pascual, A. E. (2007). Link performance parameters in IEEE 802.11: How to increase the throughput of a wireless long distance link, *White paper*, April 2007.

	- Kodialam, M., and Nandagopal. T. (2005). Characterizing the capacity region in multi-radio multi-channel wireless mesh networks. *MobiCom'05,* August 28-September 2, 2005, Cologne, Germany: ISBN: 1-59593-020-5.

**Chapter 0**

**Chapter 8**

**A Correctness Proof of a Mesh**

Additional information is available at the end of the chapter

Doug Kuhlman, Ryan Moriarty, Tony Braskich, Steve Emeott and Mahesh Tripunitara

We discuss our proof of security properties of a standards-track protocol suite for authentication and key establishment using a formal verification technique. Our technique is Protocol Composition Logic (PCL) [15] (see Section 2.1). Our setting is the IEEE 802.11 Mesh Networking task group, known as 802.11s, which was formed to define extensions to IEEE 802.11 [1] to support wireless mesh networking [25]. A goal of the task group is to secure

The Mesh Security Architecture (MSA) proposal [4–7] to 802.11s consists of a definition of a key hierarchy and a suite of protocols to enable security in a wireless mesh network. The proposal includes detailed information to implement MSA within the framework defined by 802.11s, including key derivation, protocol execution, and message formatting. The suite of protocols encompasses all the necessary components to create and maintain a mesh of nodes.

• We conduct a comprehensive assessment of all 10 protocols (averaging 4 messages and 8 components) of the MSA proposal from a security standpoint and proven its correctness. We present an overview of the protocol suite and the main insights from the proof. The full details are generally unenlightening; a companion technical report [28] complements

As this is one of few instances of the proof of correctness of a substantial, standards-track protocol suite of which we are aware, we feel that this is an important contribution. • PCL has been used to prove the correctness of the IEEE 802.11i protocol suite [26]. However, 802.11s presents new challenges that have necessitated extensions to PCL for us to be able to carry out our correctness proof. We present these extensions and details from the MSA proposal that illustrate their necessity (see Section 3). We believe that the

> ©2012 Kuhlman et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0),which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly

> © 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

extensions are general enough to be useful in other work in protocol verification.

and reproduction in any medium, provided the original work is properly cited.

a mesh by utilizing existing IEEE 802.11 security mechanisms and extensions.

We describe the following three major contributions in this chapter:

cited.

**Security Architecture**

http://dx.doi.org/10.5772/49051

**1. Introduction**

this chapter.

