Channel Allocation
What is channel assignment and what are the methods of it?
Channel assignment techniques are
used extensively in frequency reuse systems to assign time-frequency resources to each user
. There are many methods of allocating a channel upon a new call arrival or handoff attempt. … The chapter goes on to discuss directed retry and moving direction based handoff schemes.
What is called fixed channel assignment strategy?
Fixed Channel Allocation is a strategy in
which fixed number of channels or voice channels are allocated to the cells
. Once the channels are allocated to the specific cells then they cannot be changed. In FCA channels are allocated in a manner that maximize Frequency reuse.
What are the types of channel assignment *?
- Fixed: FCA, fixed channel allocation: manually assigned by the network operator.
- Dynamic: DCA, dynamic channel allocation. DFS, dynamic frequency selection. Spread spectrum.
What does channel assignment means?
Channel assignment is the
process of assigning separate orthogonal channel or partially over-lapped orthogonal channels to all the nodes in the communication range
. The main motive behind assignment of channels is to reduce the interference impact and proper delivery of packets on time.
Are the methods used for channel assignment?
Abstract. Channel assignment techniques are used
extensively in frequency reuse systems to
assign time-frequency resources to each user. There are many methods of allocating a channel upon a new call arrival or handoff attempt.
What is meant by borrowing strategy in channel assignment?
Several variation exist like borrowing strategy •
A cell is allowed to borrow a channel from neighboring cell if all of its channels are occupied
• A mobile switching center (MSC) supervises such procedures and ensures that borrowing of channel does not disrupt the or interfere with any of the calls in progress in the …
What is the drawback of dynamic channel assignment?
Disadvantages. Dynamic channel allocation
schemes increases the computational as well as storage load on the system
.
What are handoff strategies?
Definition:
When a mobile moves into a different cell while a conversation is in progress
, the MSC automatically transfers the call to a new channel belonging to the new base station.
What is meant by handoff?
Handoff refers to a
process of transferring an ongoing call or data session from one channel
.
connected to the core network to another
. • Process of transferring a MS from one base station to another.
Which channel assignment strategy increases the trunking capacity of the system?
Dynamic channel assignment strategy
reduces the probability of blocking and increases the trunking capacity of the system.
Where is fixed channel allocation used?
Fixed Channel Allocation (FCA)
This type of allocation is used
to maximize frequency usage
. If a user makes a call and cell is occupied then call is blocked. Borrowing channels from other cell solves this problem.
What is a frequency reuse?
Technique
for using a specified range of frequencies more than once in the same radio system
so that the total capacity of the system is increased without increasing its allocated bandwidth.
What is dynamic channel assignment?
Dynamic Channel Assignment (DCA)
assigns the channels to the cells dynamically according to traffic demand
, and hence, can provide higher capacity (or lower call blocking probability), fidelity and quality of service than the fixed assignment schemes.
Under what circumstances static channel assignment is used?
Static channel allocation scheme is particularly suitable for
situations where there are a small number of fixed users having a steady flow of uniform network traffic
. The allocation technique is simple and so the additional overhead of a complex algorithm need not be incurred.
What is handoff explain with example?
A handoff may occur
when there is a transfer of duties from the large cell to the smaller cell and vice versa
. For example, there is a traveling user moving within the jurisdiction of a large cell. If the traveler stops, then the jurisdiction is transferred to a microcell to relieve the load on the large cell.
