User equipment and procedure for handling possible out-of-synchronization condition in UMTS terrestrial radio access network for time division duplexing mode

{
  "publication_number": "US6456826B1",
  "country": "US",
  "kind": "B1",
  "title": "User equipment and procedure for handling possible out-of-synchronization condition in UMTS terrestrial radio access network for time division duplexing mode",
  "abstract": "An out-of-synchronization condition for a Universal Mobile Telecommunications System (UMTS) is defined for a situation in which it may be difficult to distinguish an out-of-synchronization condition in a downlink dedicated channel from interference on that channel. A request is sent on an uplink from a user equipment (UE) to a base station transceiver (BST) for increased power on a downlink channel experiencing a possible frames out-of-synchronization condition, which may instead be a possible interference condition, so as to attempt to eliminate the possible interference. After a first selected period of time without eliminating the possible interference problem, the uplink is terminated unless a broadcast downlink channel is determined to be experiencing interference below a selected level, in which case the UE is allowed to continue to send the request for increased power. Only after a second selected period of time without eliminating the possible interference problem is the uplink terminated.",
  "claims": [
    "1. Method for use by user equipment (UE) in a mobile telecommunications system, comprising the steps of: sending power control commands on an uplink from a UE to a base station transceiver (BST) for controlling power on a downlink channel experiencing a possible frames out-of-synchronization condition which may instead be a possible interference condition so as to attempt to eliminate said possible interference condition by increased power, and terminating said uplink after a first selected period of time without eliminating said possible interference problem unless a broadcast downlink channel is determined to be experiencing interference below a selected level in which case said UE continues to send said power control commands until after a second selected period of time without eliminating said possible interference problem after which said uplink is terminated.",
    "2. Method for use by user equipment (UE) in a mobile telecommunications system, comprising the steps of: sensing in each UE a parameter having a magnitude indicative of a possible out-of-synchronization condition of each frame of a radio downlink channel from a base station transceiver to the UE, for providing a sensed signal have a magnitude indicative thereof, comparing said sensed signal to a threshold for providing a possible frame out-of-sync signal for each frame for which said sensed signal exceeds said threshold, sending on a radio uplink from the mobile station to the BST, in response to said frame out-of-sync signal, a power control command for increased power on said radio downlink, incrementing, in response to each frame out-of-sync signal, a counter of possible frame out-of-sync signals, for providing a count signal indicative of a number of frames possibly out-of-synchronization, and comparing said count signal to a count threshold for providing a shutdown uplink signal in the presence of said count signal equalling or exceeding said count threshold.",
    "3. The method of claim 2, further comprising the steps of: delaying said providing said shutdown uplink signal in the presence of a downlink broadcast channel that is functioning with interference at an acceptable level and continuing said sending said power control command on said radio uplink from the UE to the BST for increased power on said radio downlink, said incrementing said counter, and said comparing said count signal but now to a selected increased count threshold for providing said shutdown uplink signal in the presence of said count signal equalling or exceeding said selected increased count threshold.",
    "4. Method for use in a mobile telecommunications system having plural cells, each cell having a base station transceiver (BST) for communicating over multiple radio links at the same time with corresponding multiple mobile stations (UEs) in the cell and over additional radio links with corresponding additional UEs nearby but in other cells, comprising the steps of: sensing in each UE a parameter having a magnitude indicative of a possible out-of-synchronization condition of each frame of a radio downlink channel from the BST to the UE, for providing a sensed signal having a magnitude indicative thereof, comparing said sensed signal to a threshold, for providing a possible frame out-of-sync signal for each frame for which said sensed signal exceeds said threshold, determining if a downlink broadcast channel is functioning properly for providing a broadcast channel (BCCH) health signal, providing a shutdown uplink signal in the absence of said BCCH health signal and otherwise, sending on a radio uplink from the UE to the BST, in response to both said BCCH health signal and said frame out-of-sync signal, a power control command for increased power on said radio downlink, incrementing in response to each frame out-of-sync signal, a counter of possible frame out-of-sync signals, for providing a count signal indicative of a number of frames possibly out-of-synchronization, and comparing said count signal to a count threshold for providing said shutdown uplink signal in the presence of said count signal equalling or exceeding said count threshold regardless of the presence or absence of said BCCH health signal.",
    "5. User equipment (UE) for use in a mobile telecommunications system, comprising: means for sending a power control command (TPC) on an uplink (UL) from said UE to a base station transceiver (BST) for increased power on a downlink (DL) channel experiencing a possible frames out-of-synchronization condition which may instead be a possible interference condition so as to attempt to eliminate said possible interference condition by increased power, and means for terminating said uplink after a first selected period of time without eliminating said possible interference problem unless a broadcast downlink channel is determined to be experiencing interference below a selected level in which case said UE continues to send said power control command until after a second selected period of time without eliminating said possible interference problem after which said uplink is terminated.",
    "6. User equipment (UE) for use in a mobile telecommunications system, comprising: means for sensing in each UE a parameter having a magnitude indicative of a possible out-of-synchronization condition of each frame of a radio downlink channel from a base station transceiver (BST) to the UE, for providing a sensed signal have a magnitude indicative thereof, means for comparing said sensed signal to a threshold for providing a possible frame out-of-sync signal for each frame for which said sensed signal exceeds said threshold, means for sending on a radio uplink from the UE to the BST, in response to said frame out-of-sync signal, a power control command (TPC) for increased power on said radio downlink, means for providing, in response to each possible frame out-of-sync signal, a count signal indicative of a number of frames possibly out-of-synchronization, and means for comparing said count signal to a count threshold for providing a shutdown uplink signal in the presence of said count signal equaling or exceeding said count threshold.",
    "7. The UE of claim 6, further comprising: means for delaying said providing said shutdown uplink signal in the presence of a downlink broadcast channel that is functioning with interference at an acceptable level whereby said sending a power control command on said radio uplink from the UE to the BST for increased power on said radio downlink is continued for a selected period.",
    "8. Apparatus for use in a mobile telecommunications system having plural cells, each cell having a base station transceiver (BST) for communicating over multiple radio links at the same time with corresponding multiple mobile stations (UEs) in the cell and over additional radio links with corresponding additional UEs nearby but in other cells, comprising: means for sensing in each UE a parameter having a magnitude indicative of a possible out-of-synchronization condition of each frame of a radio downlink channel from the BST to the UE, for providing a sensed signal having a magnitude indicative thereof, means for comparing said sensed signal to a threshold, for providing a possible frame out-of-sync signal for each frame for which said sensed signal exceeds said threshold, means for determining if a downlink broadcast channel is functioning properly for providing a broadcast channel (BCCH) health signal, means for providing a shutdown uplink signal to said BTS from said UE in the absence of said BCCH health signal, means for sending on a radio uplink from the UE to the BST, in response to both said BCCH health signal and said frame out-of-sync signal, a power command signal for increased power on said radio downlink, means for incrementing in response to each frame out-of-sync signal, a counter of possible frame out-of-sync signals, for providing a count signal indicative of a number of frames possibly out-of-synchronization, and means for comparing said count signal to a count threshold for providing said shutdown uplink signal in the presence of said count signal equaling or exceeding said count threshold regardless of the presence or absence of said BCCH health signal.",
    "9. Method for use by user equipment (UE) in a mobile telecommunications system, comprising the steps of: providing, in response to a parameter signal (126) received by said UE over a downlink from a base station transceiver (BST), a signal (138) indicative of a possible improper functioning of a downlink channel; providing, in response to a common channel downlink signal (158) having a magnitude indicative of proper functioning thereof, a common channel downlink health signal (154); and providing, in response to said signal (138) indicative of possible improper functioning of a downlink channel and said common channel health signal (154), a shutdown uplink command signal (152).",
    "10. The method of claim 9, further comprising the step of providing, in response to said signal (138) indicative of possible improper functioning of said downlink channel, an uplink power command signal (120) from the UE to the BST for increased power on said downlink channel.",
    "11. The method of claim 9, wherein said step of providing a signal (138) indicative of possible improper functioning of a downlink channel comprises the steps of: sensing said parameter signal (126) having a magnitude indicative of said possible improper functioning of a downlink channel, for providing a sensed signal (132) having a magnitude indicative thereof, and comparing said magnitude of said sensed signal (132) to a parameter threshold signal (134) having a magnitude indicative of a selected threshold, for providing said signal (138) indicative of possible improper functioning of a downlink channel.",
    "12. The method of claim 9, wherein said step of providing said health signal (154) comprises the steps of: sensing said common channel downlink signal (158) for providing a sensed common channel downlink signal (162), and comparing said sensed common channel downlink signal (162) to a threshold signal (166) for providing said common channel health signal (154).",
    "13. The method of claim 9, wherein said step of providing a shutdown uplink command signal (152) comprises the steps of: counting instances of said signal (138) indicative of possible improper functioning of a downlink channel for providing a count signal (142), comparing said count signal (142) to a count threshold signal (146, 147) for providing said shutdown uplink command signal (152) in the presence of said count signal exceeding said count threshold signal.",
    "14. The method of claim 13, further comprising the step of selecting said count threshold signal (146, 147) in response to said common channel health signal (154).",
    "15. Method for use by user equipment (UE) in a mobile telecommunications system, comprising the steps of: providing, in response to a parameter signal (126) received by said UE over a downlink from a base station transceiver (BST), a signal (138) indicative of a possible improper functioning of a downlink channel; providing, in response to a common channel downlink signal (158) having a magnitude indicative of proper or improper functioning thereof, a common channel downlink health signal (154); and providing, in response to said signal (138) indicative of possible improper functioning of a downlink channel and said common channel health signal (154), a shutdown uplink signal (152) to said BST.",
    "16. The method of claim 15, further comprising the step of providing, in response to said signal (138) indicative of possible improper functioning of said downlink channel, an uplink power control command signal (120) from the UE to the BST for increased power on said downlink channel.",
    "17. The method of claim 15, wherein said step of providing a signal (138) indicative of possible improper functioning of a downlink channel comprises the steps of: sensing said parameter signal (126) having a magnitude indicative of said possible improper functioning of a downlink channel, for providing a sensed signal (132) having a magnitude indicative thereof, and comparing said magnitude of said sensed signal (132) to a parameter threshold signal (134) having a magnitude indicative of a selected threshold, for providing said signal (138) indicative of possible improper functioning of a downlink channel.",
    "18. The method of claim 15, wherein said step of providing said health signal (154) comprises the steps of: sensing said common channel downlink signal (158) for providing a sensed common channel downlink signal (162), and comparing said sensed common channel downlink signal (162) to a threshold signal (166) for providing said common channel health signal (154).",
    "19. The method of claim 15, wherein said step of providing a shutdown uplink command signal (152) comprises the steps of: counting instances of said signal (138) indicative of possible improper functioning of a downlink channel for providing a count signal (142), comparing said count signal (142) to a count threshold signal (146, 147) for providing said shutdown uplink command signal (152) in the presence of said count signal exceeding said count threshold signal.",
    "20. The method of claim 19, further comprising the step of selecting said count threshold signal (146, 147) in response to said common channel health signal (154).",
    "21. User equipment (UE) for use in a mobile telecommunications system, comprising: means (128) for providing, in response to a parameter signal (126) received by said UE over a downlink from a base station transceiver (BST), a signal (138) indicative of a possible improper functioning of a downlink channel; means (156) for providing, in response to a common channel downlink signal (158) having a magnitude indicative of proper functioning thereof, a common channel downlink health signal (154); and means (139) for providing, in response to said signal (138) indicative of possible improper functioning of a downlink channel and in response to said common channel health signal (154), a shutdown uplink command signal (152).",
    "22. The UE of claim 21, further comprising means (118) for providing, in response to said signal (138) indicative of possible improper functioning of said downlink channel, an uplink power command signal (120) from the UE to the BST for increased power on said downlink channel.",
    "23. The UE of claim 21, wherein said means (128) for providing a signal (138) indicative of possible improper functioning of a downlink channel comprises: means (130) for sensing said parameter signal (126) having a magnitude indicative of said possible improper functioning of a downlink channel, for providing a sensed signal (132) having a magnitude indicative thereof, and means (136) for comparing said magnitude of said sensed signal (132) to a parameter threshold signal (134) having a magnitude indicative of a selected threshold, for providing said signal (138) indicative of possible improper functioning of a downlink channel.",
    "24. The UE of claim 21, wherein said means (156) for providing said health signal (154) comprises: means (160) for sensing said common channel downlink signal (158) for providing a sensed common channel downlink signal (162), and means (164) for comparing said sensed common channel downlink signal (162) to a threshold signal (166) for providing said common channel health signal (154).",
    "25. The UE of claim 21, wherein said means (139) for providing a shutdown uplink command signal (152) comprises: means (140) for counting instances of said signal (138) indicative of possible improper functioning of a downlink channel for providing a count signal (142), means (144) for comparing said count signal (142) to a count threshold signal (146, 147) for providing said shutdown uplink command signal (152) in the presence of said count signal exceeding said count threshold signal.",
    "26. The UE of claim 25, further comprising means (150, 153 b) for selecting said count threshold signal (146, 147) in response to said common channel health signal (154)."
  ],
  "description_excerpt": "1. Technical Field\n\nThis invention relates to mobile telecommunications and, more particularly, to defining how to handle an out-of-synchronization condition for UMTS where it may be difficult to distinguish an out-of-synchronization condition in a downlink dedicated channel from interference in that channel.\n\n2. Discussion of Related Art\n\nCurrently in the development of the Universal Mobile Telecommunications System (UMTS), there is no procedure defined on how the user equipment (UE) is supposed to handle an out-of-synchronization condition when it occurs. The synchronization model for UMTS is shown in the 3 GPP Technical specification TS 25.401v1.0.0 (1999-04) “UTRAN Overall Description”, at pp. 19-27. Further details can be found in the 3GPP Technical Specification TS 25.402v3.0.0 (2000-01) “Synchronization in UTRAN Stage 2”, and in other documents cross-referenced therein.\n\nA generic solution that has been applied, for example, in IS-95, could be considered, based on the cyclic redundancy code (CRC) check results. With the IS-95 solution, time division duplex (TDD) specific issues are not taken into account, and the DTX (battery saving feature on a cellular phone that cuts back the output power when the speaker stops speaking) structure with UTRAN (UMTS Terrestrial Radio Access Network) TDD does not provide the CRC check in every frame, as in IS-95.\n\nThere is therefore a need to define how to handle an out-of-synchronization condition for UMTS.\n\nIt is an object of the present invention to define how to handle an out-of-synchronization condition for UMTS.",
  "cpc": [
    "H04W 52/288",
    "H04B 7/005",
    "H04W 56/0015",
    "Y02D 30/70"
  ],
  "ipc": [
    "H04B 7/005",
    "H04B 7/26",
    "H04W 52/28"
  ],
  "assignees": [
    "Nokia Mobile Phones Ltd"
  ],
  "inventors": [
    "Antti Toskala",
    "Mirko Aksentijevic"
  ],
  "filing_date": "2000-02-25",
  "publication_date": "2002-09-24",
  "grant_date": "2002-09-24",
  "priority_date": "2000-02-25",
  "application_number": "US-51341700-A",
  "family_id": "24043173",
  "cited_by_count": 74,
  "citations": [
    "US5008953A",
    "US5375253A",
    "US5959983A",
    "EP0936831A1",
    "WO1999053701A2"
  ]
}