Hiperlan:Hiperlan stands for High Performance Radio Local Area Network. It is a wireless LAN standard. It was started in 1992; Initiated by RES-10 group of ETSI, and later the standard was approved in 1996.
The Hiperlan standard family has four different versions:
1. Hiperlan 1,
2. Hiperlan 2,
3. Hiper Access, and
Hiperlan 1:The standard covers physical layer and Data link layer (MAC part). The standard provides hierarchical independence with Elimination-Yield Non-Preemptive Multiple Access mechanism (EY-NPMA) by introducing a new sub layer called the CAC (channel access and control sub layer). The physical layer provides the FSK modulation used in HIPERLAN 1. The MAC layer provides control for routing, security and power saving facilities.
Requirement of Hiperlan 1 defined by ETSI are given below.
Data rate up to 23.52 Mbps
Coverage area up to 100m
Support time bound service
Frequency of operation was 5.2 GHz
Hiperlan 2:The standard covers physical layer, DLC, convergence layers. The standard supports both connectionless oriented and connection oriented network. It supports centralized and ad hoc topologies. The physical layer uses orthogonal frequency division multiplexing (OFDM) modulation scheme. The data link control layer consists of three parts such as MAC, Control, and data part. The convergence layer adapts new service requests from higher layer and also performs segmentation and reassembly on different sized packets. The Hiperlan 2 supports both DES and Triple-DES algorithm for strong encryption.
Requirement of Hiperlan 2 is given below.The data rate varies for different modulation scheme and ranges up to 54 Mbps.
CODED bits per OFDM symbol is from 48 to 288.
Band frequency ranges from 4.5 to 5 GHz.
Hiper Access:The Hiper Access covers physical layers, DLC and convergence layer. It is the newer version of Hiperlan providing remote access. The data rate is up to 58 Mbps, 5 GHz band.
Hiperlink:It is used in wireless broad interconnect. It also covers physical layers, DLC and convergence layer. The data rate is up to 155 Mbps with 17 GHz bandwidth.
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