HIPER LAN (High Performance Radio LAN). Two main standards families for Wireless Lan: IEEE 802.11...

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HIPER LAN (High Performance Radio LAN)

Transcript of HIPER LAN (High Performance Radio LAN). Two main standards families for Wireless Lan: IEEE 802.11...

Page 1: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

HIPER LAN(High Performance Radio LAN)

Page 2: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

Two main standards families for Wireless Lan: IEEE 802.11 (802.11b, 802.11a, 802.11g...) ETSI Hiperlan (Hiperlan Type 1, Type 2,

HiperAccess, HiperLink...)

HiperLAN Family

Hiperlan 1 Hiperlan2 HiperAccess HiperLinkDescription Wireless

EthernetWireless ATM Wireless Local

LoopWireless Point-

to-PointFreq. Range 5GHz 5GHz 5GHz 17GHz

PHY Bit Rate 23.5Mbps 6~54Mbps ~25Mbps

(data rate)

~155Mbps

(data rate)

Page 3: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

Motivation of HiperLAN

Massive Growth in wireless and mobile communications

Emergence of multimedia applications

Demands for high-speed Internet access

Deregulation of the telecommunications industry

Page 4: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

The History, Present and Future HiperLAN Type 1

Developed by ETSI during 1991 to 1996

Goal: to achieve higher data rate than IEEE 802.11 data rates: 1~2 Mbps, and to be used in ad hoc networking of portable devices

Support asynchronous data transfer, carrier-sense multiple access multiple access with collision avoidance (CSMA/CA), no QoS guaranteed.

Page 5: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

HiperLAN Type 2

Goal: Providing high-speed (raw bit rate ~54Mbps) communications access to different broadband core networks and moving terminals

Features: connection-oriented, QoS guaranteed, security mechanism, highly flexibility

HiperAccess and HiperLink

In parallel to developing the HIPERLAN Type 2 standards, ETSI BRAN has started work on standards complementary to HIPERLAN Type 2

Page 6: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

MAC

CAC

PHY

HiperLAN Type 1 Reference ModelPHY

MAC

ECACF DCC

RLC

DLC

CL

HiperLAN Type 2 Reference Model

Control Plane User Plane

MAC: Medium Access Sublayer EC: Error ControlCAC: Channel Access Control Sublayer RLC: Radio Link ControlPHY: Physical Layer RRC: Radio Resource ControlDLC: Data Link Control Layer ACF: Association Control FunctionCL: Convergence Layer DCC: DLC Connection Control

Architecture

RRC

Page 7: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

CAC: Channel Access Control Sublayer

This sub layer deals with the access request to the channels.

The accomplishing of the request is dependent on the usage of the channel and the priority request.

Page 8: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

HIPERLAN2 Protocol Stack

Page 9: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

DLC: MAC Sublayer The medium access control creates frames of 2 ms duration as

shown in Figure. With a constant symbol length of four μs this results in 500 OFDM symbols.

Page 10: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

Each MAC frame is further sub-divided into four phases with variable boundaries:

Broadcast phase: The AP of a cell broadcasts the content of the current frame plus information about the cell (identification, status, resources).

Downlink phase: Transmission of user data from an AP to the MTs.

Uplink phase: Transmission of user data from MTs to an AP.

Random access phase: Capacity requests from already registered MTs and access requests from non-registered MTs.

Page 11: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

HiperLAN2 defines six different so-called transport channels for data transfer in the above listed phases. These transport channels describe the basic message format within a MAC frame.

Broadcast channel (BCH): This channel conveys basic information for the radio cell to all MTs. This comprises the identification and current transmission power of the AP. The length is 15 bytes.

Frame channel (FCH): This channel contains a directory of the downlink and uplink phases (LCHs, SCHs, and empty parts). This also comprises the PHY mode used. The length is a multiple of 27 bytes.

Page 12: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

Access feedback channel (ACH): This channel gives feedback to MTs regarding the random access during the RCH of the previous frame. The length is 9 bytes.

Long transport channel (LCH): This channel transports user and control data for downlinks and uplinks. The length is 54 bytes.

Short transport channel (SCH): This channel transports control data for downlinks and uplinks. The length is 9 bytes.

Random channel (RCH): This channel is needed to give an MT the opportunity to send information to the AP/CC even without a granted SCH. The length is 9 bytes.

Page 13: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

DLC: Error Control

Acknowledged mode: selective-repeat ARQ

Repetition mode: typically used for broadcast

Unacknowledged mode: unreliable, low latency

DLC: other features

Radio network functions: Dynamic frequency selection; handover; link adaptation; multibeam antennas; power control

QoS support: Appropriate error control mode selected; Scheduling performed at MAC level; link adaptation; internal functions (admission, congestion control, and dropping mechanisms) for avoiding overload

Page 14: HIPER LAN (High Performance Radio LAN).  Two main standards families for Wireless Lan:  IEEE 802.11 (802.11b, 802.11a, 802.11g...)  ETSI Hiperlan (Hiperlan.

Radio Link Control Sublayer

It offers connection oriented systems ,offering QoS.

Three main control functions Association control function (ACF): authentication, key

management, association, disassociation, encryption

Radio resource control function (RRC): handover, dynamic frequency selection, mobile terminal alive/absent, power saving, power control

DLC user connection control function (DCC): setup and release of user connections, multicast and broadcast

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Convergence Layer

HiperLAN2 supports two different types of CLs: cell-based and packet-based.

cell-based CL expects data packets of fixed size (cells, e.g., ATM cells).

packet-based CL handles packets that are variable in size (e.g., Ethernet )