Wimax standards and Security The Wimax

Part II
Security

10

An Overview of WiMAX Security
Eduardo B. Fernandez and Michael VanHilst
CONTENTS

1. 
   Introduction 197
   
2. 
   Network Aspects 198
   
3. 
   WiMAX Security 199
   
4. 
   Conclusions 203
   

References 204



10.1 Introduction

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The IEEE 802.16 protocol is also called WiMAX, which stands for worldwide interoperability of microwave access. It addresses high-bandwidth wide-area access between a service provider base station (BS) and multiple subscriber stations (SSs), often referred to as the “last mile’’ in reference to neighbor- hood connections between subscribers’ homes and a phone or cable company office. In fact, important parts of the protocol are based on the DOCSIS BPI (data over cable service interface specifications: baseline privacy plus inter- face specification) [3] protocol used in cable modems. The original 802.16 standard covers line-of-sight connections in the 10–66 GHz range, supporting speeds up to 280 Mbps over distances up to 50 km (30 mi.). 802.16a cov- ers nonline-of-sight connections in the 2–11 GHz range, supporting speeds up to 75 Mbps over distances of 5–8 km (3–5 mi.). 802.16a also adds features for mesh networks, while the 802.16e standard adds support for mobility (i.e., station handoff) [4].
As a wireless protocol, WiMAX has an additional set of security threats
not faced in cable systems. Because the DOCSIS protocol was developed for cable modems, not wireless systems, the original 802.16 standard does not provide enough security for the intended purpose. The standard threats for wireless systems still apply to WiMAX systems, in particular all the attacks to the higher levels [5,6]. Later extensions correct some of the weaknesses.


197

We present here an overview of the security aspects of this standard. We use unified modeling language (UML) class and sequence diagrams to describe architectural aspects. These are conceptual diagrams, intended to define the information in each unit and do not reflect implementation details. The reader is referred to Ref. 9 or similar textbooks for introductions to UML. The idea is to present a high-level overview that can be read before getting into the details of the standard or more advanced discussions.

Section 10.2 discusses the networking aspects of this protocol and Section 10.3 presents an overview of its basic security aspects. We end with some conclusions and ideas for future work.

2.