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If you're an engineer involved in developing wireless LAN systems, this valuable book will give you a practical understanding of the latest wireless LAN standards and their implementation. The book clearly explains the two principal standards, IEEE 802.11 and IrDA, plus the HIPERLAN standard, and explores their real-world applications through commercially available equipment. Specific scenarios explain how WLAN systems can be built and integrated with cabled systems.
"...provides engineers with the latest wireless LAN standards & their implementation...explains the two principle standards, IEEE 802.11 & IrDA, plus the HIPERLAN standard...explores their real-world applications."
A wireless future can be envisioned with the following features:
This book focuses on WLAN standards. The rest of this chapter discusses the evolution of the wireless standards discussed in previous chapters (IEEE 802.11, HIPERLAN, and IrDA), and presents new wireless standards that can provide LAN services but that have been defined for a broader range of applications. This is indicative of a developing trend: standards that cover multiple applications, providing a link to communication terminals while offering enough flexibility to be employed in a variety of scenarios.
Another important trend that is worth mentioning is the evolutionary nature of current standards. They are not fixed iionce and for alllc but are being updated again and again to add new features or to find new applications. The current speed of technological innovation is determinant on this fact. On many occasions, the new version of a standard can be implemented with the same hardware, by means of updating the software.
Some manufacturers, with the purpose of accelerating the adoption of HIPERLAN/1-based products worldwide, have formed the HIPERLAN Alliance. Market promotion, spectrum lobbying, and cooperation with other standardization bodies are among the objectives of the HIPERLAN Alliance. More information can be found in . To our knowledge, there are no HIPERLAN products on the market at the moment, but they are expected to appear very soon.
HIPERLAN/2, originally based on WATM, has extended its scope for providing WLAN services and for interacting with core networks of different kinds, such as ATM, IP, and UMTS.
Figure 6.1 shows the reference model for HIPERLAN/2. A convergence layer provides connectivity with the core network. Thus, the standard is open in that it can use other networks in the future, with the only specification being that of the corresponding convergence layer. A good description of this standard can be found in , a document that also includes references to the related ETSI technical documents.
The most important distinguishing characteristic of HIPERLAN/1 is its centralized MAC, which supports QoS functions. HIPERLAN/2 can operate in a centralized mode, which allows the implementation of radio access to a fixed point. Thus, a network can be implemented to cover entire buildings through the deployment of APs in a cellular structure. It can also operate in ad hoc networks, without the need for APs, but in this case one of the devices must operate as a central controller. The central controller can be any of the devices in the network, and can change if, for example, the current central controller leaves the net....
Preface. Biographies. Acknowledgements. Glossary. Introduction - Introduction to Wireless Local Area Networks. The Need for Standardization. Future Trends. The IrDa Standard - Introduction to IrDA; General Description. Physical Layer (SIR). Serial Infrared Link Access Protocol (IrLAP). IrDA Link Management Protocol (Ir-LMP). IrDA Transport Protocol: TinyTP. LAN Access Extensions for Link Management Protocol: IrLAN. The IEEE 802.11 Standard - Introduction to IEEE 802.11; General Description. Medium Access Control (MAC) for the IEEE 802.11 Wireless LANs. Physical Layer for IEEE 802.11 Wireless LANs; Radio systems. Physical Layer for IEEE 802.11 Wireless LANs. IR Systems. Conclusions and Applications. The HIPERLAN Standard - Introduction; Terminology. Physical Layer (PHY). HIPERLAN Channel Access Control (CAC). HIPERLAN Medium Access Control (MAC). Conclusions on HIPERLAN Type 1. Future Bran Standards. Application Scenarios - Introduction. The Application Scenarios. Wireless LAN Technologies and Products. Conclusions. Upcoming Standards and Future Trends - Introduction; Is the Future Wireless? The Evolution of HIPERLAN. The Evolution of IEEE 802.11. Forthcoming IR Standards. Other RF Standards: DECT, Bluetooth, wATM, HomeRF, etc. Conclusions.