HIPERLAN (HIgh PErformance Radio LAN) is a Wireless LAN standard. It is a European alternative for the IEEE 802.11 standards (the IEEE is an American organization). It is defined by the European Telecommunications Standards Institute (ETSI). In ETSI the standards are defined by the BRAN project (Broadband Radio Access Networks). The HIPERLAN standard family has four different versions.
The standard covers the physical and the Media Access Control part of the Data Link layers like 802.11. There is a new sublayer called Channel Access and Control sublayer (CAC). This sublayer deals with the access requests to the channels. The accomplishing of the request is dependent on the usage of the channel and the priority of the request.
CAC layer provides hierarchical independence with Elimination-Yield Non-Preemptive Multiple Access mechanism (EY-NPMA). EY-NPMA codes priority choices and other functions into one variable length radio pulse preceding the packet data. EY-NPMA enables the network to function with few collisions even though there would be a large number of users. Multimedia applications work in HIPERLAN because of EY-NPMA priority mechanism. MAC layer defines protocols for routing, security and power saving and provides naturally data transfer to the upper layers.
On the physical layer FSK and GMSK modulations are used in HIPERLAN/1.
HIPERLAN features:
HIPERLAN does not conflict with microwave and other kitchen appliances, which are on 2.4GHz.
Basic services are data, sound, and video transmission. The emphasis is in the quality of these services (QoS).
The standard covers Physical, Data Link Control and Convergence layers. Convergence layer takes care of service dependent functionality between DLC and Network layer (OSI 3). Convergence sublayers can be used also on the physical layer to connect IP, ATM or UMTS networks. This feature makes HIPERLAN/2 suitable for the wireless connection of various networks.
On the physical layer BPSK, QPSK, 16QAM or 64QAM modulations are used.
Good security measures are offered by HIPERLAN/2. The data are secured with DES or Triple DES algorithms. The access point and the wireless terminal can authenticate each other.
Others believe that the superior technical performance of HIPERLAN/2 can offer new services that 802.11 variants are incapable of delivering. As of 2006 HIPERLAN has largely failed in the marketplace compared to 802.11.
The development of 802.11n, which will define the next level of performance in WLANs, is not paralleled by any further attempt at HIPERLAN activity.
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"HIPERLAN".
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