Wimax standards and Security The Wimax

James T. Yu
CONTENTS

1. 
   Introduction 58
   
2. 
   Background 58
   
   1. 
      QoS Definition 58
      
   2. 
      QoS in Circuit-Switching Network 60
      
   3. 
      QoS of Packet-Switched Network 60
      
      1. 
         Connectionless Service (Ethernet or IP) 60
         
      2. 
         Asynchronous Transfer Mode 60
         
   4. 
      QoS of Wireless Lan and 802.11e 61
      

4.3 IEEE 802.16 62

1. 
   Basic Operation 62
   
2. 
   Service Flow 64
   
3. 
   QoS in IEEE 802.16 65
   
4. 
   Admission Control 67
   
5. 
   QoS Scheduling 67
   
   1. 
      UGS Scheduling 67
      
   2. 
      rtPS Scheduling 68
      
   3. 
      nrtPS Scheduling 69
      
   4. 
      BE Scheduling 69
      

4. 
   Simulation of IEEE 802.16 QoS Operation 69
   
   1. 
      Admission Control 69
      
   2. 
      Simulation of IEEE 802.16 QoS Scheduling 72
      
5. 
   Conclusions 74
   
6. 
   Acknowledgments 74
   

References 75
57

1. 
   Introduction
   

Over the last few years, we have seen the continual growth and demand for broadband wireless access (BWA) for residential, business, and mobile customers. With the standardization of IEEE 802.16-2004 [1], the industry formed the WiMAX Forum to support product certification of conformance to the standard and to promote interoperability among different vendors’ products. A recent data shows 48% increase in the WiMAX equipment market, from $45M in fourth quarter of 2005 to $70M in first quarter of 2006 [2]. The same report predicts that the WiMAX market will grow to more than $1B by 2009. The success of WiFi (as specified in 802.11) is evident on the wireless local area network (WLAN), and many people expect to see the same growth of WiMAX on the wide area network (WAN). In general, LAN is based on broadcast technology with connectionless services, and WAN is based on point-to-point (P2P) or point-to-multipoint (P2MP) technology with connection-oriented services.
Supporting Quality of Service (QoS) is essential for WAN because it allows
for more efficient operations on the service providers’ network to meet various customer demands. A service provider can offer differentiated services with specific Service Level Agreement (SLA) and charge the services accordingly. The IEEE 802.16 standard supports QoS on a per connection basis, where a con- nection is defined between the base station (BS) and a subscriber station (SS). A connection could be either from the BS to an SS (a downlink or DL con- nection) or from an SS to the BS (an uplink or UL connection). An SS could establish multiple connections to the BS, where each connection has its own QoS. An SS requests for bandwidth allocation on a DL or UL channel and the BS allocates the bandwidth to the SS based on the available resources, which is in the radio frequency spectrum. After granting the bandwidth, the BS enters the request into a priority queue based on its QoS. The BS then applies a scheduling algorithm to determine when and how to serve the jobs in the queues. The IEEE 802.16 standard provides a protocol for the request/grant procedure. However, the standard does not provide the QoS scheduling algo- rithm and its implementation is open to the product vendors. In this chapter, we present an architecture and an operation procedure of admission control and job scheduling, and develop a simulation model to study the network performance under various load conditions.

2.