Sorry, I didn't think I needed to reply anymore.Let's start at the customer's end of the connection - the customer has a wireless modem, that wireless modem communicates with one base-station at a time, a base-station is essentially all of the radio equipment usually mounted on a mast [aka cell tower], that is usually where the wireless bit ends. Base-stations need to be able to transfer data relayed to & from the customer's wireless modem, this will usually be done using wired links aka backhaul links - typically fibre optic, if there is a cluster of many base-stations in an area, what might happen is microwave links [wireless] might relay data to a centralised backhaul link that is effectively shared by all base-stations within the cluster, but essentially there is still a wired backhaul link that connects one or more base-stations to the core network.
Base-station congestion is different to backhaul link congestion. The symptoms of a congested base-station will usually be not being able to connect or frequent disconnects - this is bcos base-stations typically cannot cope with an unlimited number of wireless modems connected to that one base-station, usually base-stations are clustered to allow for mobile handoffs to another less congested base-station. Backhaul links have xMbits/s capacity, aka bandwidth, [typically Mbits/s in SA - other countries it is likely to be Gbits/s] now when the amount of data being transferred per second through a backhaul link approaches x, then customers whose data gets relayed through that backhaul link, will start to see sporadic congestion - typically dropped packets & retransmissions which will obviously severely affect the throughput|speed of their connection.
That is about as best I can explain it without writing a whole essay on the subject.Firstly, Cell Breathing is a 3G network phenomenon - 2G networks do not experience Cell Breathing - 2G networks have other problems like a limited number of timeslots - 3G networks do not use timeslots, also Cell Breathing in 3G networks is by design and not a flaw in the system. The coverage footprint of 2G base-stations is basically constant, whereas the coverage footprint of a 3G base-station fluctuates, i.e. the 3G cell "breathes" which means that the effective coverage footprint of a particular 3G base-station will expand when congestion of a 3G base-station reduces, and when congestion increases the the coverage footprint will reduce. This means that 3G modems further away from a 3G base-station will usually be handed off to another less congested base-station when a congestion threshold is reached and the coverage footprint reduces to leave a modem outside of that coverage footprint.
Also worth noting that, often 2G and 3G base-stations are physically attached to the same cell tower mast, however the coverage footprint of a 2G base-station is considerably larger [and constant] compared to the 3G base-station - this is mainly due to the higher frequency used for 3G transmissions, so considerably more 3G base-stations are required in any given cluster to properly cover an area, than is necessary for 2G clusters.
will look at it again when i have time.
