HIPERLAN2 is a wireless network standard that operates at 5GHz, offering data rates up to 54Mbps. It supports quality of service, security, and mobility. There are two modes of operation: centralized, where devices connect through an access point, and direct, for device-to-device connections. The protocol stack includes physical, data link control, and convergence layers to interface with different network protocols like Ethernet, Firewire, and ATM. Handovers between access points can be done at the radio or network level.

1. HIPERLAN 2

2. HIPERLAN2
HIPERLAN2 wireless network works at 5 GHz and offers data rates of up to 54 Mbit/s
including QoS support and enhanced security features.
Various features of HIPERLAN2
 High-throughput transmission
 Connection-oriented
 Quality of service support
 Dynamic frequency selection
 Security support
 Mobility support
 Application and network independence
 Power saver

3. HiperLAN2 architecture and handover
scenarios
APC – Access Point Controller
APT – Access Point Transceiver
MT – Mobile Terminal

4. (a) Radio handover (Inter-APT/Intra-AP):
This handover type is handled within the AP, no external interaction is needed.
Example
 The terminal MT3, moves from one APT to another of the same AP.
 All context data for the connections are already in the AP (encryption keys, authentication, and connection
parameters) and does not have to be renegotiated.
(b) Network handover (Inter-AP/Intra-network):
Example
 MT2 moves from one AP to another. In this case, the core network and higher layers are also involved.
 This handover might be supported by the core Network.
 Otherwise, the MT must provide the required information similar to the situation during a new association.

5. Mode of operation of HiperLAN2
Mode of operation
 Centralized mode
 Direct mode
Centralized Mode
Direct Mode

6. HiperLAN2 protocol stack
1. Physical Layer
2. Data Link Control (DLC) Layer
3. Convergence Layer
 Data link control (DLC) layer :
 MAC functions,
 RLC sublayer
 Error control functions.

7. Data link control layer in HiperLAN2
Basic structure of HiperLAN2 MAC frames

8. Transport Channels for HiperLAN2
 Broadcast Channel (BCH)
 Frame Channel (FCH)
 Access feedback Channel (ACH)
 Long Transport Channel (LCH)
 Short Transport Channel (SCH)
 Random Channel (RCH)

9. Convergence Layer
• As the physical layer and the data link layer are independent of specific
core network protocols, a special convergence layer (CL) is needed to
adapt to the specific features of these network protocols.
• HiperLAN2 supports two different types of CLs: cell-based and packet-
based.
• The cell-based CL expects data packets of fixed size (cells, e.g., ATM
cells), while the packet-based CL handles packets that are variable in
size.
Three examples of convergence layers follow:
• Ethernet
• IEEE 1394 (Firewire)
• ATM