Subject: Mobile Communication and Computing

Topic: Wireless Local Area Networks

Difficulty: High

Hiperlan/1 physical layer. Hyperlan/1

1. Hiperlan stands High performance Radio LAN.
2. It is wireless LAN srandard.
3. It is defined by the European Telecommunication Standards Institute (ESTI).
4. HiperLAN 1 is the first version of Hiperlan.
5. Hiperlan 1 supports both Infrastructure based and Ad-hoc Network.

Hiperlan/1 Physical Layer

1. The function of Hiperlan/1 physical layer are as follows:

a. Modulation and Demodulation.

b. Bit and frame synchronization.

c. Forward error correction mechanisms.

d. Channel sensing.

1. Hiperlan/1 provide 3 mandatory and 2 optional channels.

Mandatory channels

a. Channel 0 : 5.18Ghz

b. Channel 1 : 5.20GHz

c. Channel 2 : 5.22GHz

Optional Channels

a. Channel 3 :5.25GHz

b. Channel 4 :5.25GHz

1. Hiperlan/1 uses Non Differential Gaussian Minimum Shift Keying(GMSK)
2. It uses Decision Feedback Equalizer (DFE) to remove inter symbol interference.
3. To minimize the error at physical layer, it uses BCH error correcting codes.
4. This code is able to correct a single error and detect two random errors.
5. Figure shows Hiperlan/1 Data Packet format used at physical layer.
6. It shows the data packet and ACK packet.