[Help with code transmission in RF or IF]

thnx 4 the replies
i already thought of using RF but the big problem comes when u have to identify more than one buses coming to the station
u have to decide whether buses will transmit same frequencies or different ones and abt interfernce b/w signals ::)

and if ure having multiple frequencies then receiver has to check all frequencies automatically . also once announced theres no need to announce the same bus again.
now these r some of the problems which ive encountered with this project
now wht should i do??? ::)

[Help with code transmission in RF or IF]

hi,
im doing an electronics&comm project as part of my curriculum.
im thinking of an announcer system to be placed in bus stations which
receives a particular code transmitted from a bus and announces to the passengers about its arrival.
Is RF is a good choice 4 transmission ??RF has better coverage than
IR doesnt it?
also there r 2 ways i thought 4 code tranmission
1)DTMF signals - is simple but only few capabilities (no: of buses) :-\

2)Digital transmission-of course more complex,also needing a uC
but anyway im planning to implement it without a PC by using a
uC :-\



so have any of u got anything that could help me out ???
bye!!