# US 2004/0170148 A1 · Frequency hopping control channel in a radio communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2004/0170148 A1 - Document ID: US20040170148A1 - Status: Published application - Kind: A1 - Application number: 10/482,042 - Filed: 2003-12-29 - Published: 2004-09-02 - Earliest claimed: 2003-12-29 - Inventors: Jarri Parkkinen; Esa Jarvela - Web page: https://patentgrep.com/patent/US20040170148A1 ## CPC - H04W 72/563: of the wireless resources - H04B 7/2656: {for structure of frame, burst} - H04W 72/542: using measured or perceived quality - H04W 76/28: Discontinuous transmission [DTX]; Discontinuous reception [DRX] - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION ## Abstract The invention relates to a method for positioning mandatory time division multiple access (TDMA) frames which are mandatory to be transmitted during discontinuous transmissions (DTX) of TDMA frames in traffic channels (TCH) by a fixed sub-system of a radio communications system. It is assumed that said TDMA frames are transmitted using cyclic frequency hopping with two different frequencies. In order to improve air interface measurement methods in a radio access system, it is proposed that said mandatory TDMA frames are positioned for each sub-channel that can be employed as TCH in a way that said mandatory TDMA frames are always transmitted using both of said two different frequencies in the respective sub-channel within a predetermined number of TDMA frames. The invention equally relates to a corresponding radio communications network, a corresponding base station and mobile terminal and a corresponding subset of mandatory TDMA frames. ## Claims ### Claim 1 Method for positioning mandatory time division multiple access (TDMA) frames which are mandatory to be transmitted during discontinuous transmissions (DTX) of TDMA frames in traffic channels (TCH) by a fixed sub-system of a radio communications system, wherein said TDMA frames are transmitted using cyclic frequency hopping with two different frequencies, and wherein said mandatory TDMA frames are positioned for each channel that can be employed as traffic channel in a way that said mandatory TDMA frames are always transmitted using both of said two different frequencies in the respective channel within a predetermined number of TDMA frames. ### Claim 2 (depends on 1) Method according to claim 1, wherein said mandatory TDMA frames are slow TCH associated control channel (SACCH/T) frames and frames of a subset of TDMA frames predetermined for a traffic channel, and wherein SACCH/T frames assigned to respectively one of the traffic channels are transmitted at least with a first frequency while the TDMA frames of a subset for said TCH are transmitted at least with the other frequency. ### Claim 3 (depends on 2) Method according to claim 2, wherein a silence descriptor (SID) frame is transmitted as mandatory TDMA frame in case no user signaling or speech is to be transmitted in a current TDMA frame of a subset predetermined for speech transmissions on one of the traffic channels. ### Claim 4 Method according to one of the preceding claims, wherein said predetermined number of TDMA frames is 104. ### Claim 5 Method according to one of the preceding claims, wherein said traffic channels include sub-channels employed for half rate transmissions. ### Claim 6 (depends on 2, 3, 4, 5) Method according to one of claims 2 to 5, wherein a subset of TDMA frames predetermined for speech transmissions on one of said traffic channels includes the TDMA frames with frame numbers modulo 104 of 39, 41, 43, 45, 91, 93, 95, and 97. ### Claim 7 (depends on 6) Method according to claim 6, wherein said traffic channel is the first of two sub-channels employed for half rate transmissions. ### Claim 8 Method according to one of the preceding claims, wherein a mobile terminal receiving said transmitted mandatory TDMA frames measures the signal level of said mandatory TDMA frames for determining a RXLEV_SUB value indicative of the level of received signals. ### Claim 9 Method according to one of the preceding claims employed in a GSM communications system. ### Claim 10 Method according to one of the preceding claims employed in an EDGE communications system. ### Claim 11 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) A radio communications system comprising a fixed sub-system system with transmitting means for transmitting signals in time division multiple access (TDMA) frames and employing for the transmission of TDMA frames on a traffic channel (TCH) a cyclic frequency hopping with two different frequencies; and processing means for positioning mandatory TDMA frames for discontinuous transmissions (DTX) in a traffic channel according to one of claims 1 to 10, said radio communications system further comprising a mobile terminal with means for receiving said mandatory TDMA frames and means for measuring the reception level of said received mandatory TDMA frames. ### Claim 12 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) A fixed sub-system for a radio communications system comprising: transmitting means for transmitting signals in time division multiple access (TDMA) frames and employing for the transmission of TDMA frames on a traffic channel (TCH) a cyclic frequency hopping with two different frequencies; and processing means for positioning mandatory TDMA frames for discontinuous transmissions (DTX) in a traffic channel according to one of claims 1 to 10. ### Claim 13 A mobile terminal comprising means for receiving time division multiple access (TDMA) frames and for measuring during discontinuous transmissions (DTX) of a fixed sub-system of a radio communications system employing a cyclic frequency hopping with two different frequencies at least the reception levels of received mandatory TDMA frames, wherein the mandatory TDMA frames were transmitted for each channel employed as traffic channel (TCH) in a way that both frequencies are used within a predetermined number of TDMA frames ### Claim 14 Subset of time division multiple access (TDMA) frames of a first of two sub-channels used as half rate traffic channels (TCH) for transmissions from a fixed sub-system to mobile terminals of a radio communications system, which subset defines TDMA frames which are mandatory to be transmitted in discontinuous transmissions (DTX) on said first sub-channel, said subset comprising the TDMA frames with frame numbers modulo 104 of “39”, “41”, “143”, “145”, “91”, “193”, “951”, and “197”.