Difference between Centralized radio resource management and Distributed radio resource management in LTE

Question

What is the difference between Centralized RRM and Distributed RRM?

I heard that LTE has Distributed RRM. Previous generation had Centralized RRM. Can some please explain the differences between them.

Answer 1

Finally, I found the answer for this question. In GSM, GPRS/EDGE, UMTS, HSPA there is a master controller, that controls all the base stations. There is Base Station Controller (BSC) in case of GSM, GPRS/EDGE, and the Radio Network Controller for 3G systesms (UMTS, HSPA).

2G/2.5G-->BSC,
3G-->RNC.

This is termed as Centralized Radio Resource Management.

But in LTE, most of the functions of RNC are integrated into eNodeBs(Base stations in LTE). So, there is no master controller, which controls the base stations (eNodeB) in LTE. This is called Distributed Radio Resource Management. Also called as flat architecture.

Reference:https://www.youtube.com/watch?v=1_x9axf0jlk&list=PLE6yE0jB6BTOeXSdhXeOxVQPhnZ0R3ltM

Answer 2

The Centralized RRM will be located in a separate node or kind of gateway entity of network and shall control many cells (having Distributed RRM). The number of distributed RRM shall be less than that of Centralized RRM in a typical deployment of a network operator. Distributed RRM will be located in cell and communicate with one centralized RRM (typically communication will be with one centralized RRM and in some case it can be more that in it as per deployment).

The Centralized RRM shall mostly include functionalities related to Radio admission control, Radio Bearer Control, Dynamic Resources Allocation based on interaction with Distrbuted RRM. The Distributed RRM shall encompass functionalities that are very near to the radio technologies w.r.t MAC and PHY, like QoS management, MAC configuration, PHY configuration etc...