question about the concept of tight bound

[insatiable]

hi all. about the communication system performance, like capacity bound, many papers mentiond the upper or lower bound is tight or tighter than the others bound. i do not know what is the 'tight ' mean here ? can anybody explain it. thanks

 

[wajahat]

Hi,
tight bound means a bound which can be achieved.One can compare this to bounds which have been defined but not achieved so far.

regards
wajahat