LTE TDD frame

LTE frame structures used for TDD

36.211 frame structure type 2 (DL / UL / SSF)

Correct choice of Configuration value is essential when setting the UL/DL ratio for CableFree LTE networks using TDD bands

  • Choose a configuration with more “D”s in the frame means greater proportion of Downlink Data (normal for most Internet /ISP applications)
  • Choose a configuration with more “U”s in a frame when you need a greater proportion of Uplink Data.    This is when most traffic is uplinked e.g. CCTV applications, from remote cameras to base
  • Choose a configuration with equal “D” and “U” for a balanced network (equal up/down)
Frame configuration Number
Configuration 3GPP
release
Downlink to uplink
switch point
periodicity (ms)
Subframe number Number of subframes / frame
0 1 2 3 4 5 6 7 8 9 D [DL] U [UL] S [SSF]
0 8 5 D S U U U D S U U U 2 6 2
1 8 5 D S U U D D S U U D 4 4 2
2 8 5 D S U D D D S U D D 6 2 2
3 8 10 D S U U U D D D D D 6 3 1
4 8 10 D S U U D D D D D D 7 2 1
5 8 10 D S U D D D D D D D 8 1 1
6 8 5 D S U U U D S U U D 3 5 2
  • D – Downlink subframe
  • S – Special subframe (see below)
  • U – Uplink subframe

Graphical view of one TDD frame (10ms)

LTE TDD Frame
LTE TDD Frame

SSF Special SubFrame, normal CP (Dw / GP / Up)

SSF configuration NUmber
Configuration 3GPP
release
DwPTS UpPTS Number of slots / subframe
(Ts) (Ts) Dw GP Up
0 8 6592 2192 3 10 1
1 8 19760 2192 9 4 1
2 8 21952 2192 10 3 1
3 8 24144 2192 11 2 1
4 8 26336 2192 12 1 1
5 8 6592 4384 3 9 2
6 8 19760 4384 9 3 2
7 8 21952 4384 10 2 2
8 8 24144 4384 11 1 2
9 11 13168 4384 6 6 2
  • DwPTS – Downlink Pilot Time Slot
  • UpPTS – Uplink Pilot Time Slot
  • GP – Guard period

Graphical view of a Special Subframe (1ms)

LTE TDD SubFrame
LTE TDD SubFrame

For Further Information

Please contact us with any questions on CableFree Wireless Technology and 4G/LTE

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