Clean Claims Indian Patent Application No. 1505/CHENP/2012
Date: 22nd November, 2018
We Claim:
1. A method for communication from a second mobile station to a base station or
vice versa, the method comprising:
- communicating by the second mobile station or the base station, in a given multiframe,
- a first SACCH slot associated with the second mobile station via a second VAMOS subchannel,
- a redundant second SACCH slot associated with the second mobile station,
- the second SACCH slot communicated via the second VAMOS subchannel, with the second VAMOS subchannel being in discontinuous transmission mode, or
- the second SACCH slot communicated via a first VAMOS subchannel, with the first VAMOS subchannel being in discontinuous transmission mode, wherein the first and second VAMOS subchannels share a common time slot and have the same carrier frequency.
2. The method of claim 1, further comprising:
- communicating, in the multiframe, a third SACCH slot associated with a first
mobile station via the first VAMOS subchannel,
wherein the first SACCH slot being in a different TDMA frame than the third SACCH slot.
3. The method of claim 2, wherein
- the first and second VAMOS subchannels are operated at full rate;
- the first SACCH slot is communicated in TDMA frame number 8 of the multiframe, the TDMA frames of which being numbered from 0 to 25; and
- the third SACCH slot is communicated in TDMA frame number 12 of the multiframe.

Clean Claims Indian Patent Application No. 1505/CHENP/2012
Date: 22nd November, 2018
4. The method of claim 1, wherein
the first and second VAMOS subchannels are operated at full rate;
- the second SACCH slot is communicated via the second VAMOS subchannel in TDMA frame 11 of the multiframe, the TDMA frames of which being numbered from 0 to 25, with the second VAMOS subchannel being in discontinuous transmission mode, or
- the second SACCH slot is communicated via the first VAMOS subchannel in TDMA frame 10 of the multiframe, the TDMA frames of which being numbered from 0 to 25, with the first VAMOS subchannel being in discontinuous transmission mode.
5. The method of claim 2, wherein the first and second VAMOS subchannels are
operated at half rate; and
- the first SACCH slot is communicated in TDMA frame number 8 of the multiframe, the TDMA frames of which being numbered from 0 to 25, and the third SACCH slot is communicated in TDMA frame number 12 of the multiframe, or
- the first SACCH slot is communicated in TDMA frame number 22 of the multiframe, the TDMA frames of which being numbered from 0 to 25, and the third SACCH slot is communicated in TDMA frame number 25 of the multiframe.
6. The method of claim 5, wherein
- the first SACCH slot is communicated in TDMA frame number 8 of the
multiframe, the third SACCH slot is communicated in TDMA frame number
12 of the multiframe and the second SACCH slot is communicated in TDMA
frame number 10, with the second VAMOS subchannel being in discontinuous
transmission mode, or

Clean Claims Indian Patent Application No. 1505/CHENP/2012
Date: 22nd November, 2018
- the first SACCH slot is communicated in TDMA frame number 22 of the multiframe, the third SACCH slot is communicated in TDMA frame number 25 of the multiframe and the second SACCH slot is communicated in TDMA frame number 24, with the second VAMOS subchannel being in discontinuous transmission mode, or
- the first SACCH slot is communicated in TDMA frame number 8 of the multiframe, the third SACCH slot is communicated in TDMA frame number 12 of the multiframe and the second SACCH slot is communicated in TDMA frame number 10, with the first VAMOS subchannel being in discontinuous transmission mode, or
- the first SACCH slot is communicated in TDMA frame number 22 of the multiframe, the third SACCH slot is communicated in TDMA frame number 25 of the multiframe and the second SACCH slot is communicated in TDMA frame number 24, with the first VAMOS subchannel being in discontinuous transmission mode.

7. The method of claim 1, where a SACCH block associated with the second mobile station is encoded in four first SACCH slots of four subsequent multiframes.
8. The method of claim 7, wherein - for each of the four subsequent multiframes - the second SACCH slot – if communicated – in the respective multiframe is a repetition of the first SACCH slot in the same respective multiframe.
9. The method of claim 7, wherein the second SACCH slot in at least one of the four subsequent multiframes is a repetition of the first SACCH slot of a different one of the four subsequent multiframes.

Clean Claims Indian Patent Application No. 1505/CHENP/2012
Date: 22nd November, 2018
10. The method of claim 9, wherein
- the second SACCH slot – if communicated - in the first of the subsequent multiframes is a repetition of the first SACCH slot in the fourth of the subsequent multiframes;
- the second SACCH slot – if communicated - in the second of the subsequent multiframes is a repetition of the first SACCH slot in the third of the subsequent multiframes;
- the second SACCH slot – if communicated - in the third of the subsequent multiframes is a repetition of the first SACCH slot in the second of the subsequent multiframes; and
- the second SACCH slot – if communicated - in the fourth of the subsequent multiframes is a repetition of the first SACCH slot in the first of the subsequent multiframes.
11. The method of claim 9, wherein
- the second SACCH slot – if communicated - in the first of the subsequent multiframes is a repetition of the first SACCH slot in the third of the subsequent multiframes;
- the second SACCH slot – if communicated - in the second of the subsequent multiframes is a repetition of the first SACCH slot in the fourth of the subsequent multiframes;
- the second SACCH slot – if communicated - in the third of the subsequent multiframes is a repetition of the first SACCH slot in the first of the subsequent multiframes; and
- the second SACCH slot – if communicated - in the fourth of the subsequent multiframes is a repetition of the first SACCH slot in the second of the subsequent multiframes.

Clean Claims Indian Patent Application No. 1505/CHENP/2012
Date: 22nd November, 2018
12. The method of claim 7, wherein
- each second SACCH slot – if transmitted – of the four subsequent multiframes is a repetition of a respective first SACCH slot within the four subsequent multiframes; and
- the SACCH block is decoded by using the second SACCH slot of at least one of the four subsequent multiframes.
13. The method of claim 12, wherein
- the SACCH block associated with the second mobile station is encoded in the four second SACCH slots of the four subsequent multiframes; and
- the SACCH block is decoded by decoding the four second SACCH slots of the four subsequent multiframes.
14. The method of claim 12, wherein
- the SACCH block is decoded by combining at least one of the first SACCH
slots and at least one of the transmitted second SACCH slots.
15. The method of claim 1, wherein the second mobile station is a VAMOS compliant mobile station and a first mobile station is not a VMOS compliant mobile station, wherein the base station and the first mobile station communicate via the first VAMOS subchannel.
16. The method of claim 7, wherein the method further comprises:
- repeating the SACCH block after said four subsequent multiframes.
17. The method of claim 1, wherein the first and second SACCH slots are
communicated in downlink direction from the base station to the second mobile
station.

Clean Claims Indian Patent Application No. 1505/CHENP/2012
Date: 22nd November, 2018
18. The method of claim 1, wherein
- the first and second SACCH slots are communicated in uplink direction from the second mobile station to the base station; and
- the second SACCH slot is communicated via the second VAMOS subchannel, with the second VAMOS subchannel being in discontinuous transmission mode.
19. The method of claim 1, wherein
- the first and second VAMOS subchannels are operated at half rate; and
- the second SACCH slot is communicated in TDMA frame number 10, with the second VAMOS subchannel being in discontinuous transmission mode, or
- the second SACCH slot is communicated in TDMA frame number 24, with the second VAMOS subchannel being in discontinuous transmission mode, or
- the second SACCH slot is communicated in TDMA frame number 10, with the first VAMOS subchannel being in discontinuous transmission mode, or
- the second SACCH slot is communicated in TDMA frame number 24, with the first VAMOS subchannel being in discontinuous transmission mode.
20. The method of claim 1, wherein
- the second SACCH slot is communicated via the second VAMOS subchannel, when the second VAMOS subchannel is in discontinuous transmission mode,
- the second mobile station or the base station detects whether the second VAMOS subchannel is in discontinuous transmission mode and uses the second SACCH slot for decoding of a SACCH block if the second mobile station or the base station detects that the second VAMOS subchannel is in discontinuous transmission mode.

Clean Claims Indian Patent Application No. 1505/CHENP/2012
Date: 22nd November, 2018
21. The method of claim 1, wherein
- the second SACCH slot is communicated via the second VAMOS subchannel, when the second VAMOS subchannel is in discontinuous transmission mode,
- the second SACCH slot is communicated via the first VAMOS subchannel, when the first VAMOS subchannel is in discontinuous transmission mode and the second VAMOS subchannel is not in discontinuous transmission mode,
- the second mobile station
- detects whether the second VAMOS subchannel is in discontinuous transmission mode and
- uses the second SACCH slot in the second VAMOS subchannel for decoding of a SACCH block if the second mobile station detects that the second VAMOS subchannel is in discontinuous transmission mode and
- uses the second SACCH slot – if transmitted – in the first VAMOS subchannel for decoding of a SACCH block otherwise.
22. The method of claim 1, wherein
- the second SACCH slot is communicated via the second VAMOS subchannel, when the second VAMOS subchannel is in discontinuous transmission mode,
- the second SACCH slot is communicated via the first VAMOS subchannel, when the first VAMOS subchannel is in discontinuous transmission mode and the second VAMOS subchannel is not in discontinuous transmission mode,
- the base station
- detects whether the second VAMOS subchannel is in discontinuous transmission mode,
- uses the second SACCH slot in the second VAMOS subchannel for decoding of a SACCH block if the base station detects that the second VAMOS subchannel is in discontinuous transmission mode,

detects whether the first VAMOS subchannel is in discontinuous transmission mode, and
- uses the second SACCH slot in the first VAMOS subchannel for decoding of a SACCH block if the base station detects that the first VAMOS subchannel is in discontinuous transmission mode and detects that the second VAMOS subchannel is not in discontinuous transmission mode.
23. A base station configured to perform the method claimed in any of method claims 1 to 22..
24. A VAMOS compliant mobile station configured to perform the method claimed in any of method claims 1 to 22.
25. A transmitter configured to perform the method claimed in any of method claims 1 to 22.
26. A receiver configured to receive a signalto perform the method claimed in any of method claims 1 to 22.