Channel Allocation Strategies in Computer Network
Channel Allocation means to allocate the available channels to the cells in a cellular system. When a user wants to make a call request then by using channel allocation strategies their requests are fulfilled. Channel Allocation Strategies are designed in such a way that there is efficient use of frequencies, time slots and bandwidth.
Types of Channel Allocation Strategies:
These are Fixed, Dynamic, and Hybrid Channel Allocation as explained as following below.
- Fixed Channel Allocation (FCA):
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.
In cell A 20 Channels or Voice channels are allocated. If all channels are occupied and user make a call then the call is blocked. Borrowing Channels handles this type of problem. This cell borrow channels from other cells.
- Dynamic Channel Allocation (DCA):
Dynamic Channel allocation is a strategy in which channels are not permanently allocated to the cells. When a User makes a call request then Base Station (BS) send that request to the Mobile Station Center (MSC) for the allocation of channels or voice channels. This way the likelihood of blocking calls is reduced. As traffic increases more channels are assigned and vice-versa.
- Hybrid Channel Allocation (HCA):
Hybrid Channel Allocation is a combination of both Fixed Channel Allocation (FCA) and Dynamic Channel Allocation (DCA). The total number of channels or voice channels are divided into fixed and dynamic set. When a user make a call then first fixed set of channels are utilized but if all the fixed sets are busy then dynamic sets are used. The main purpose of HCA is to work efficiently under heavy traffic and to maintain a minimum S/I.