What is GSM time slot?
The GSM standard [1] specifies a TDMA frame as a combination of 8 time slots. Each time slot has a duration of 3/5200 seconds (about 0.577 ms) and a time slot number (TN) from 0 to 7. GSM frames use GMSK modulation, where one symbol is equivalent to one bit. Each time slot is 156.25 bits long.
Which time slots of a GSM TDM frame are used in traffic multiframe and control multiframe respectively?
Each GSM superframe composed of multiframes (either 26 or 51 as described below). Each GSM multiframe composed of frames (either 51 or 26 based on multiframe type). Each frame composed of 8 time slots. Hence there will be total of 2715648 TDMA frames available in GSM and the same cycle continues.
What is multiframe and multiframe control?
Traffic Multiframe Structures The 26 traffic multiframe structure is used to send information on the traffic channel. The 26 traffic multiframe structure is used to combine user data (traffic), slow control signaling (SACCH), and an idle time period.
How many carriers does GSM 900 have?
As mentioned earlier, in the GSM 900 system, the total available number of uplink and downlink carriers = 25 MHz/200 kHz = 125.
What is duration of superframe?
Wireless Personal Area Networks: Low Rate and High Rate 4 LR-WPAN can operate in an optional superframe mode. In a superframe (see Figure 20.9), a dedicated PAN coordinator transmits superframe beacons in predetermined intervals. These intervals can be as short as 15 ms or as long as 245 seconds.
What is the duration of GSM Sacch multi frame?
This lasts for approximately 4.615 ms (i.e.120/26 ms) and it forms the basic unit for the definition of logical channels. One physical channel is one burst period allocated in each TDMA frame.
What is multiframe in GSM?
A GSM Multiframe is the basic unit, and is 120 ms long. There are 26 Frames in each Multiframe, with each Frame being 4.61538 ms long (120 ms/26). Within each Frame are 8 Timeslots at 576.92 μs per Timeslot (577 μs in round numbers).
What are the different types of GSM channels?
There are two main types of GSM channels viz. physical channel and logical channel. Physical channel is specified by specific time slot/carrier frequency.
What’s the time period for a GSM time slot?
The time period for a GSM time slot is 577 microseconds. The number of data bits in a time slot depending on the type of the time slot (user data or control). The structure of the time slot can also vary dependent if the time slot is on the uplink or downlink radio channel.
How many time slots are there for ARFCN in GSM?
These logical channels are time sheduled by BTS. Always occur at beacon frequency in time slot 0, it may also take up other time slots if required by system for example 2,4,6. As shown in fig 3. each ARFCN or each channel in GSM will have 8 time slots TS0 to TS7.
How many data slots are there in a GSM radio?
The data transported by the carrier serves up to eight different users under the basic system by splitting the carrier into eight time slots. The basic carrier is able to support a data throughput of approximately 270 kbps, but as some of this supports the management overhead, the data rate allotted to each time slot is only 24.8 kbps.
Which is the most important slot in a GSM channel?
The most important slot is the time slot TS0 where in BCCH is mapped and is very useful as SI messages (system information messages) are transmitted over this channel. Following are possible channel combinations in GSM system which network (BTS) will adopt based on need of traffic channels versus signalling (control) gsm channels.