5.1 Hyperframes, superframes and multiframes

3GPP45.001General descriptionGSM/EDGE Physical layer on the radio pathRelease 17TS

A diagrammatic representation of all the time frame structures is in figure 1. The longest recurrent time period of the structure is called hyperframe and has a duration of 3 h 28 mn 53 s 760 ms (or 12 533,76 s). The TDMA frames are numbered modulo this hyperframe (TDMA frame number, or FN, from 0 to 2 715 647). This long period is needed to support cryptographic mechanisms defined in 3GPP TS 43.020.

One hyperframe is subdivided in 2 048 superframes which have a duration of 6,12 seconds. The superframe is the least common multiple of the time frame structures. The superframe is itself subdivided in multiframes; four types of multiframes exist in the system:

– a 26- multiframe (51 per superframe) with a duration of 120 ms, comprising 26 TDMA frames. This multiframe is used to carry TCH (and SACCH/T) and FACCH;

– a 51- multiframe (26 per superframe) with a duration of ≈235,4 ms (3 060/13 ms), comprising 51 TDMA frames. This multiframe is used to carry BCCH, EC-BCCH, CCCH (NCH, AGCH, PCH and RACH), EC-CCCH (EC-AGCH, EC-PCH and EC-RACH), EC-PICH and SDCCH (and SACCH/C).

– a 52-multiframe (25,5 per superframe) with a duration of 240 ms, comprising 52 TDMA frames. This multiframe is used to carry PBCCH, PCCCH (PAGCH, PPCH and PRACH), PACCH, EC-PACCH, PDTCH, EC-PDTCH, PTCCH and MPRACH. The 52-multiframe is not shown in Figure 1, but can be seen as two 26-multiframes, with TDMA frames numbered from 0 to 51. For Compact, this 52-multiframe (51 per superframe) is used to carry CFCCH, CSCH, CPBCCH, CPCCCH (CPAGCH, CPPCH, and CPRACH), PACCH, PDTCH, and PTCCH.

– a 52-multiframe (25,5 per superframe) for CTS, with a duration of 240 ms, comprising 52 TDMA frames. This multiframe is used to carry CTSCCH (CTSBCH, CTSPCH, CTSARCH and CTSAGCH). The 52-multiframe for CTS is shown in Figure 2b.

A TDMA frame, comprising eight time slots has a duration of ≈4,62 (60/13) ms.