|Idea||Segment spaced into cells or sectors.||Segments sending time into disjoint time slots demand driven or fixed patterns.||Segment the frequency band into disjoint subbands||Spread the spectrum using orthogonal codes.|
|Terminals||Only one terminal can be active in one cell or one sector.||All terminals are active for short periods of time on same frequency.||Every terminal has its own frequency uninterrupted||All terminals can be active at the same place at the same moment uninterrupted.|
|Signal separation||Cell structure, directed antennas||Synchronization in time domain||Filtering in the frequency domain.||Code plus special receivers.|
|Cell capacity||Depends on cell area||Limited||Limited||No absolute limit on channel capacity but it is an interference limited system|
|Advantages||Very simple, increases capacity per||Established fully digital, flexible||Simple, established, robust||Flexible, less frequency planning needed, soft handover|
|Disadvantages||Inflexible, antennas typically fixed||Guard space needed (multipath propagation), synchronization difficult||Inflexible, frequencies are scarce resource||Complex receivers, needs more complicated power control for senders|
|Comment||Only in combination with TDMA, FDMA or CDMA useful||Standards in fixed networks, together with FDMA or SDMA used in many mobile networks||Typically combined with TDMA and SDMA||Still faces some problems, higher complexity, lowered expectations, will be integrated with TDMA or FDMA|
Please log in to add an answer.