Wimax standards and Security The Wimax

1.8 Complementary Technologies
Technologies presented in this section are largely complementary to WiMAX. These technologies have been proven for their intended purposes and do not overlap significantly compared to the purposes WiMAX technologies were designed to serve.


1.8.1 IEEE 802.11
The widespread adoption of IEEE 802.11 has resulted in a substantial increase in the ability to connect to the Internet wirelessly. However, unlike WiMAX, IEEE 802.11 was primarily designed for local area networks. It lacks the complexity and power levels inherent in WiMAX that would be required for scalability while maintaining high levels of throughput. WiMAX tech- nologies are primarily based on time division duplex (TDD) or frequency division duplex (FDD) access methods with access slots reallocated to users as needed on a demand basis. IEEE 802.11, however, shares the media with multiple users by employing a distributed-approach version of Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), which is inherently limited when trying to scale one single channel to support many users. In this sense, the IEEE 802.11 WLAN standards address connecting local areas (within 10s or 100s of feet) most efficiently—one would not prefer the com- plexity of a WiMAX base station to support connections with maximum distances in this range. It is expected that within short ranges and limited

number of users, IEEE 802.11 will outperform WiMAX technologies signif- icantly. WiMAX deployments will not possess the bandwidth required to support many users in a city-wide coverage area with the data rates each would experience if there were one IEEE 802.11 access point for every few users. Such a scenario is typical of the home-network model, where one IEEE

802.11 access point is deployed, connected to a wired infrastructure such as a cable modem or digital subscriber line (DSL).


1.8.2 IEEE 802.15
The IEEE 802.15 family of standards focuses primarily on WPANs with ranges only on the order of 10 ft. Obviously, WiMAX technologies were not designed with this limited range in mind, but the need and demand for WPANs have become increasingly prevalent as wireless networking evolves to support a variety of platforms, including those in the home such as household appli- ances. Furthermore, mobile phones enabled with IEEE 802.15 technologies benefit from the ability to connect to other phones, computers, or devices such as headsets, albeit within a short range. As the data rate require- ments for the applications running over WPANs remain relatively small compared to WiMAX technologies, this technology clearly has delineated a niche compared to the intended use for WiMAX.





1.9 Conclusion
The momentum built up behind WiMAX technologies has reached a criti- cal point. Significant investment in research, development, products, and marketing for WiMAX has been ongoing and is expected to continue. This chapter has described other wireless networking technologies that compli- ment or compete with WiMAX technologies. It has also provided an overview of the most prevalent technologies in use today, as well as a description of the similarities and differences compared to WiMAX.





References

1. 
   IEEE 802.11-1999,