Cell Bar Access CBA

Value range:  Yes (0),  No (1)

Unit:  None

Content: Cell Bar Access, worked together with CBQ to set the priority status of the cell in idle mode for cell selection and reselection.

Recommendation:   Yes

Cell access permitted is the parameter that the network operator can set. Usually all cells allow MS to access, thus it is set as “Yes”. But in the special cases, the operator may want a cell to be used for handover service only, which can be realized by setting the parameter as “No” (CBQ should be “No”).

 

Application of CBA

 

 

Assume that area D in the diagram is a hot spot. Usually micro cell is adopted in order to have a better access performance with the limited frequency resources. And usually dual-layer network is adopted in order to reduce the handover times when MS moves at a high speed, that is, site A is established to cover the entire area A. Generally MS works in the micro cell (this can be realized by setting the priority and proper reselection parameters of the cell). When MS moves at a high speed during the conversation, the network will force MS to hand over to cell  A. If MS stays close to cell A and at the edge of micro cell when the conversation ends, as the signal quality of cell A is much better than that of micro cell, MS will not initiate the cell reselection process according to GSM specification. As cell A usually have a small capacity, it will be congested in the above case. The solution is to set the cell bar access of cell A as “No”, certainly CBQ should also be set as “No” to prohibit MS from accessing cell A directly and only permit MS to enter the coverage area of cell A by HO. In this way, MS will reselect the micro cell when the conversation ends.