This document discusses mobility management in mobile ad-hoc networks (MANETs). It begins by introducing MANETs and explaining that they are temporary networks formed spontaneously via wireless communication between mobile nodes without centralized administration. It then discusses the need for mobility management, including location management and handoff management routing protocols. It also discusses different types of node mobility and mobility models for predicting node movement patterns over time in MANETs. The document categorizes mobility models as trace-based (using real movement data) or synthetic-based (simulating realistic movement), and lists examples of models within each category like the random waypoint and reference point group mobility models.

1. Mobility management in
Adhoc Network
Aman Saurabh

2. Introduction- Mobile Ad-hoc Networks (MANET) are multi-hop temporary
communication network of mobile nodes that can communicate with one another without
the requirement of any centralized point. MANET is particularly vulnerable due to its
fundamental characteristics, such as open medium, dynamic topology, distributed
cooperation, and constrained capability. Routing plays an important role in the security of
the entire network.
A mobile ad hoc network (MANET) is a self-configuring network that is formed
spontaneously by a group of mobile devices via wireless communication channels. Nodes
in such a network cooperate by forwarding packets for each other. MANETs do not have
centralised administration or fixed network infrastructure. They are often deployed in
situations where there is no fixed network infrastructure. Applications, such as military
mobile networks, disaster relief and mine site operations, benefit from this type of
networking. Owing to the characteristics of MANETs, such as lack of infrastructural
support, dynamically changing network topologies, open and bandwidth constrained
channels and heterogeneous devices.

3. MOBILITY
MANAGEMENT
Need of Mobility Management- The mobility management provides the delivery of the
packet to the specified destination without any kind of delay. One of the basic requirements
of the mobility management is the routing protocols. There are two types of scheme in
mobility management which include location management and handoff management.
Location management routing protocol use the location of nodes for enhancing the
performance of routing protocols while Handoff management focuses on rerouting
concept. Node mobility has impact on the position of nodes and on neighbourhood
information which is necessary for communication. There are three types of mobile host
node movements, they are movement by nodes in a route, movement by subnet bridging
node and concurrent node movement. Also, it can be easily addressed through multi-hop
routing discovery.
Mobility models in ad-hoc networks exhibit the mobile user movement pattern as well as
the change in their location, velocity, speed, direction and acceleration over time. There is
direct communication between nodes in these kinds of network. In these networks, mobile
nodes communicate directly with each other. Two nodes are required to be in same
transmission for an effective communication. Intermediate nodes with routing are the
solution of this problem. Mobility models must be evaluated with respect to end to end
delay and efficient data transmission.

4. Mobility models are required to focus on individual movement patterns due to point to
point communication in cellular networks whereas ad-hoc networks are designed for
group communication. Such models are suggested to maintain movement, and efficient
transmission among nodes in real life applications. Mobility models can be categorized
based on the following criteria which is based on dimension, scale of mobility,
randomness, geographical constraints, destination oriented and by changing
parameters. There are two types of mobility models (i) Trace based mobility models
and (ii) Synthetic mobility models. Trace models provide mobility patterns based on
deterministic approach whereas synthetic models presents movements of mobile nodes
in realistic manner.

5. TRACE BASED MODEL - For predicting stability of the nodes, movement patterns
history and monitoring on periodic movements is required. Movement pattern of
nodes provide path of mobile node which maintains degree of stability in the
network.
SYNTHETIC BASED MODEL- These models are very close to real life situations.
There are two types of synthetic mobility models in ad-hoc networks. These models
are categorized in two types (i) Entity based group mobility model and (ii) Group
based mobility model.
Entity and group mobility movements: These models maintain mobile’s
traversing pattern from one place to another in a given interval of time. Each type
of models can be constrained based or statistical based mobility model. Constrained
topology based mobility models and Statistical based mobility model: In
Constrained topology based mobility models, mobile nodes have only partial
randomness where the movement of nodes is restricted by obstacles, pathways and
speed etc. In statistical mobility model, mobile nodes have total randomness where
nodes are allowed to move anywhere in the area and the speed and direction are
allowed to choose.

6. Entity and group mobility movements: These models maintain mobile’s
traversing pattern from one place to another in a given interval of time. Each type
of models can be constrained based or statistical based mobility model. Constrained
topology based mobility models and Statistical based mobility model: In
Constrained topology based mobility models, mobile nodes have only partial
randomness where the movement of nodes is restricted by obstacles, pathways and
speed etc. In statistical mobility model, mobile nodes have total randomness where
nodes are allowed to move anywhere in the area and the speed and direction are
allowed to choose.

7. SYNTHETIC BASED MODEL
Entity based mobility model
• Random Walk Mobility Model
• Random Waypoint Mobility Model
• Random Direction Mobility Model
• Gauss Markov Mobility Model
• Boundless simulation area
• Probabilistic version of Random
Walk
• City Section Mobility Model
• Brownian Motion Mobility Model
Group Based Mobility Model
• Reference Point Group Mobility
Model (RPGM)
• Column Mobility Model
• Pursue Mobility Model
• Nomadic Community Model

8. Conclusion
Mobility in ad-hoc networks is still a issue due to the dynamic
movement of the mobile nodes. The mobile ad-hoc networks
should deal with the mobility along with the power consumption.