mobile computing coe 446 network operation
DESCRIPTION
Mobile Computing COE 446 Network Operation. Tarek Sheltami KFUPM CCSE COE http://faculty.kfupm.edu.sa/coe/tarek/coe446.htm. Principles of Wireless Networks K. Pahlavan and P. Krishnamurth. Outline. Handoff Management Architectural Issues in Handoff Handoff Decision Time Algorithms - PowerPoint PPT PresentationTRANSCRIPT
April 21, 2023 1
Mobile Computing COE 446
Network OperationTarek Sheltami
KFUPMCCSECOE
http://faculty.kfupm.edu.sa/coe/tarek/coe446.htm
Principles of Wireless Networks
K. Pahlavan and P. Krishnamurth
April 21, 2023 2
Handoff Management
Architectural Issues in Handoff
Handoff Decision Time Algorithms
Types of Handoffs
Outline
April 21, 2023 3
Handoff ManagementHandoff Management
1.Architectural Issues in Handoff
Set of protocols to notify all related entities of a particular connection that a handoff has been executed and the connection has to be redefined
In voice network, MT selects the BS that is serving its location
When an MT moves from one point of attachment to another, the old serving point of attachment has to be informed about the change (dissociation)
Other network components involved in routing mechanism have to be aware of the handoff in order to seamlessly continue the ongoing connection of the call
Mobile Management
April 21, 2023 4
Handoff are classified according to the connection creation
Seamless handoff and hard handoff
Handoffs are classified into:
1. Network Controlled Handoff (NCHO)
2. Mobile Controlled Handoff (MCHO)
3. Mobile Assisted Handoff (MAHO)
Mobile Management
April 21, 2023 5
(Cellular Digital Packet Data)
April 21, 2023 6
Handoff ManagementHandoff Management
2.Handoff Decision Time Algorithms
Traditional handoff algorithms are based on the RSS. Some of them are as follows:
1. RSS
2. RSS plus Threshold
3. RSS plus Hysteresis
4. RSS, Hysteresis and Threshold
5. Algorithms plus Dwell Timer
Mobile Management
April 21, 2023 7
April 21, 2023 8
April 21, 2023 9
Time051015202530354045BS1-50-57-56-44-49-55-60-60.5-55-52BS2-49-53-46-54-45-47-56-60-55-56BS3-66-55-45-47-57-58-46-54-55-62
A mobile terminal is receiving signals from 3 BSs at the handoff region .The handoff decision is made at each sampling time according to the below table. The MT is initially connected with BS1 .
Show the handoff transitions between BSs for each of the following algorithms:•RSS•RSS + -60 dBm Threshold•RSS + Hysteresis 10 dBm•RSS + Hsyteresis 5 dBm + -55 dBm Threshold
Example
April 21, 2023 10
BS3 BS2 BS1 Time 0 5 10 15 20 25 30 35 40 45
BS3 BS2 BS1 Time 0 5 10 15 20 25 30 35 40 45
BS3 BS2 BS1 Time 0 5 10 15 20 25 30 35 40 45
BS3 BS2 BS1 Time 0 5 10 15 20 25 30 35 40 45
Time051015202530354045BS1-50-57-56-44-49-55-60-60.5-55-52BS2-49-53-46-54-45-47-56-60-55-56BS3-66-55-45-47-57-58-46-54-55-62
April 21, 2023 11
Handoff ManagementHandoff Management
2.Handoff Decision Time Algorithms
The performance of handoff algorithms measures have been considered such as call blocking probability, handoff blocking probability, delay between handoff request and execution, and call dropping probability
Handoff rate is related to the ping-pong effect and algorithms are designed to minimize the number of unnecessary handoffs
Mobile Management
April 21, 2023 12
Generic Handoff Management ProcessGeneric Handoff Management Process
1. Handoff decision is made and initiated
2. MT register with new visiting database via handoff messages
3. New visiting database communicates with the home database to get the subscriber profile and for authentication
4. Home database responds to the new visiting database with authentication of the MT
5. Home database sends messages to the old visiting database to cancel registration
6. The old visiting database flushes or redirects to the new visiting database and removes the MT from its list
Mobile Management
April 21, 2023 13
April 21, 2023 14
Handoff ManagementHandoff Management
Types of Handoffs:
1. Intracell, two channels
2. Intercell intradomain handoff, between two BSs associated with the same database
3. Intercell interdomain handoff, between two BSs with different database
Mobile Management