What Is Slot Time?

A time slot is the smallest unit of circuit-switched summary information transfer.

Timeslot is a serial self-multiplexing part of time slot information dedicated to a single channel. It usually refers to a voice channel (64kbps) in PCM E1 and T1 signals. It is a time slice in time division multiplexing mode (TDM).

PCM E1 and T1 are two international multiplexing systems: 30 / 32-channel frame structure (E1) and 24-channel frame structure (T1). China adopts a 30 / 32-channel frame structure, that is, each frame occupies 125µs and is divided into 32 time slots, but only transmits 30-channel voice information.

1.E1 is 2M

According to the time slot characteristics of E1 in PCM coding, E1 is divided into 32 time slots TS0-TS31. Each time slot is 64K, where TS0 is the frame synchronization code. TS16 is a signaling time slot. When signaling (co-channel signaling or associated signaling) is used, this time slot is used to transmit signaling, and users cannot use it to transmit data. So the 2M PCM pattern has

PCM30: There are 30 time slots available for PCM30 users, TS1-TS15, TS17-TS31. TS16 transmits signaling without CRC check.

PCM31: There are 31 time slots available for PCM30 users, TS1-TS15, TS16-TS31. TS16 does not transmit signaling and has no CRC check.

PCM30C: There are 30 time slots available for PCM30 users, TS1-TS15, TS17-TS31. TS16 transmits signaling with CRC check.

PCM31C: PCM30 users have 31 available time slots, TS1-TS15, TS16-TS31. TS16 does not transmit signaling and has a CRC check.

A time slot can be understood as a channel. Multiple people share one resource and use time-sharing methods. One time slot is equivalent to one channel. The channel can be compared to an RJ45 network cable. There are 11 available channels. Considering that there is a signal overlapping area between two adjacent wireless APs, in order to ensure that the signal channels used in this part of the area cannot cover each other, specifically, wireless APs whose signals cover each other must use different channels, otherwise it is easy to cause Signals between wireless APs interfere with each other, which causes the overall performance of the wireless network to decrease. ^[3]