EARLANG B: ( Also called Block calls Cleared) that is for every user who requests service it is assumed that user is given a immediate access to a channel if one is available. If no channel is available the user is blocked without access and is free to try again later.
EARLANG B: (Also called Block calls Delayed) is one in which a que is provided to hold calls which are blocked. If a channel is not available immediately the call request may be delayed until a channel becomes available.
One timeslot of a TDMA-frame on one carrier is referred to as a physical channel. There are 8 physical channels per carrier in GSM,channel 0-7(timeslot 0-7).
A great variety of information must be transmitted between BTS and the MS,for e.g. user data and control signaling. Depending on the kind of information transmitted we refer to different logical channels. These logical channels are mapped on physical channel.