Method and Arrangement for Power Control Handling

Abstract

A network node, a wireless device and methods therein are provided for handling transmit power control for contemporaneous links related to multi-connectivity. A method in a network node involves obtaining a separate maximum transmit power value for a wireless device per contemporaneous link; and transmitting at least one of the obtained maximum transmit power values to another network node, thereby enabling the other network node to control the transmit power of the wireless device for a link corresponding to at least one of the obtained maximum transmit power values

1 . A method performed in a network node, for enabling transmit power control of a wireless device that is configured to support two or more contemporaneous links with two or more corresponding wireless access points, the method comprising:
 obtaining ( 501 ,  601 ) a separate maximum transmit power value for the wireless device per contemporaneous link, and   transmitting ( 502 ) at least one of the obtained maximum transmit power values to another network node, thereby enabling the other network node to control the transmit power of the wireless device for a link corresponding to at least one of the obtained maximum transmit power values.   
     
     
         2 . The method according to  claim 1 , wherein the separate maximum transmit power values are determined based on a total power constraint for the wireless device. 
     
     
         3 . The method according to  claim 2 , wherein the separate maximum transmit power values are determined such that the sum of all the separate maximum transmit power values does not exceed the maximum allowed transmit power for the wireless device. 
     
     
         4 . The method according to  claim 2 , wherein the separate maximum transmit power values are determined such that the sum of all the separate maximum transmit power values does not exceed the maximum allowed transmit power for the wireless device minus a threshold value. 
     
     
         5 . The method according to any of  claims 2 - 4 , wherein the separate maximum transmit power values are determined based on one or more of: a power headroom report from the wireless device, information on a Reference Signal Received Power, RSRP, or a Reference Signal Received Quality, RSRQ, of the wireless device, a buffer status of the wireless device, priority of a corresponding contemporaneous link. 
     
     
         6 . The method according to  claim 5 , wherein the separate maximum transmit power values are determined based on one or more of the following rules:
 determining a higher transmit power value for a link with a larger corresponding buffer size, as compared to another contemporaneous link;   determining a higher transmit power value for a link which has a higher priority, as compared to another contemporaneous link;   determining a higher transmit power value for a link having a lower RSRP and/or RSRQ value, as compared to another contemporaneous link.   
     
     
         7 . The method according to any of  claims 2 - 6 , wherein different maximum transmit power values for a link are determined for different subframes and/or for different channels or signals. 
     
     
         8 . The method according to any of  claims 1 - 7 , wherein the maximum transmit power values are determined based on different criteria during different time intervals. 
     
     
         9 . The method according to  claims 7  or  8 , comprising determining a time-varying pattern for the maximum transmit power value for one or more of the contemporaneous links. 
     
     
         10 . The method according to any of  claims 1 - 9 , wherein the network node is a wireless access point. 
     
     
         11 . The method according to any of the preceding claims, wherein the network node is a Main eNB and the other network node is a Secondary eNB. 
     
     
         12 . The method according to any of the  claims 1 - 10 , wherein the other network node is a Main eNB or a Secondary eNB. 
     
     
         13 . The method according to any of the  claims 10 - 12 , further comprising:
 signaling at least one of the obtained maximum transmit power values to the wireless device.   
     
     
         14 . The method according to any of  claims 10 - 13 , further comprising:
 scheduling the wireless device in the uplink based on the maximum transmit power value corresponding to the link between the network node and the wireless device.   
     
     
         15 . The method according to any of  claims 10 - 14 , further comprising:
 receiving a power headroom report from the wireless device; and   scheduling the wireless device on one of the contemporaneous links, based on the maximum transmit power for that link, and the received power headroom report.   
     
     
         16 . The method according to  claim 15 , further comprising determining the actual power headroom available to the wireless device for transmission on one of the contemporaneous links, based on the received power headroom report and on the obtained maximum transmit power value for that link. 
     
     
         17 . The method according to any of the preceding claims wherein the separate maximum transmit power values are determined by the network node. 
     
     
         18 . The method according to any of  claims 1 - 16 , wherein the separate maximum transmit power value for the wireless device per contemporaneous link are received from another network node. 
     
     
         19 . A method performed in a network node, for controlling the transmit power of a wireless device that is configured to support two or more contemporaneous links with two or more corresponding wireless access points, the method comprising:
 obtaining ( 601 ) a separate maximum transmit power value for the wireless device per contemporaneous link; and   signaling ( 602 ) the separate maximum transmit power values to the wireless device.   
     
     
         20 . The method according to  claim 19 , wherein the separate maximum transmit power values are determined based on a total power constraint for the wireless device. 
     
     
         21 . The method according to  claim 20 , wherein the separate maximum transmit power values are determined such that the sum of all the separate maximum transmit power values does not exceed the maximum allowed transmit power for the wireless device. 
     
     
         22 . The method according to  claim 20 , wherein the separate maximum transmit power values are determined such that the sum of all the separate maximum transmit power values does not exceed the maximum allowed transmit power for the wireless device minus a threshold value. 
     
     
         23 . The method according to any of  claims 20 - 22 , wherein the separate maximum transmit power values are determined based on one or more of: a power headroom report from the wireless device, information on a Reference Signal Received Power, RSRP, or a Reference Signal Received Quality, RSRQ, of the wireless device, a buffer status of the wireless device, priority of a corresponding contemporaneous link. 
     
     
         24 . The method according to  claim 23 , wherein the separate maximum transmit power values are determined based on one or more of the following rules:
 determining a higher transmit power value for a link with a larger corresponding buffer size, as compared to another contemporaneous link;   determining a higher transmit power value for a link which has a higher priority, as compared to another contemporaneous link;   determining a higher transmit power value for a link having a lower RSRP and/or RSRQ value, as compared to another contemporaneous link.   
     
     
         25 . The method according to any of  claims 20 - 24 , wherein different maximum transmit power values for a link are determined for different subframes and/or for different channels or signals. 
     
     
         26 . The method according to any of  claims 20 - 25 , wherein the maximum transmit power values are determined based on different criteria during different time intervals. 
     
     
         27 . The method according to  claims 25  or  26 , comprising determining a time-varying pattern for the maximum transmit power value for one or more of the contemporaneous links. 
     
     
         28 . The method according to any of  claims 19 - 27 , wherein the network node is a wireless access point. 
     
     
         29 . The method according to any  claims 19 - 28 , wherein the network node is a Main eNB. 
     
     
         30 . The method according to any of  claims 28 - 29 , further comprising:
 scheduling the wireless device in the uplink based on the maximum transmit power value corresponding to the link between the network node and the wireless device.   
     
     
         31 . The method according to any of  claims 28 - 30 , further comprising:
 receiving a power headroom report from the wireless device; and   scheduling the wireless device on one of the contemporaneous links, based on the maximum transmit power for that link, and the received power headroom report.   
     
     
         32 . The method according to  claim 31 , further comprising determining the actual available power headroom available to the wireless device for transmission on one of the contemporaneous links, based on the received power headroom report and on the obtained maximum transmit power value for that link. 
     
     
         33 . The method according to any of the  claims 19 - 32  wherein the separate maximum transmit power values are determined by the network node. 
     
     
         34 . The method according to any of  claims 19 - 32 , wherein the separate maximum transmit power value for the wireless device per contemporaneous link are received from another network node. 
     
     
         35 . A method performed in a network node for scheduling a wireless device, the wireless device being configured to support two or more contemporaneous links with two or more corresponding wireless access points, the method comprising:
 obtaining ( 701 ,  801 ) a separate maximum transmit power value for the wireless device per contemporaneous link;   receiving ( 703 ,  802 ) a power headroom report from the wireless device; and   scheduling ( 704 ,  804 ) the wireless device on one of the contemporaneous links, based on the obtained maximum transmit power value for that link, and on the received power headroom report.   
     
     
         36 . The method according to  claim 35 , further comprising determining ( 804 ) the actual available power headroom available to the wireless device for transmission on one of the contemporaneous links, based on the received power headroom report and on the obtained maximum transmit power value for that link. 
     
     
         37 . The method according to  claim 35  or  36 , wherein scheduling the wireless device on one of the contemporaneous links comprises selecting one or more of the following parameters for the uplink grant based on the obtained maximum transmit power value for that link: amount of physical resource blocks assigned to the terminal, a transport block size assigned to the terminal, a modulation and coding scheme assigned to the terminal. 
     
     
         38 . The method according to any of  claims 35 - 37 , wherein the separate maximum transmit power values are determined based on a total power constraint for the wireless device. 
     
     
         39 . The method according to  claim 38 , wherein the separate maximum transmit power values are determined such that the sum of all the separate maximum transmit power values does not exceed the maximum allowed transmit power for the wireless device. 
     
     
         40 . The method according to  claim 38 , wherein the separate maximum transmit power values are determined such that the sum of all the separate maximum transmit power values does not exceed the maximum allowed transmit power for the wireless device minus a threshold value. 
     
     
         41 . The method according to any of  claims 35 - 40 , wherein the separate maximum transmit power values are further determined based on one or more of: information on a Reference Signal Received Power, RSRP, or a Reference Signal Received Quality, RSRQ, of the wireless device, a buffer status of the wireless device, priority of a corresponding contemporaneous link. 
     
     
         42 . The method according to  claim 41 , wherein the separate maximum transmit power values are determined based on one or more of the following rules:
 determining a higher transmit power value for a link with a larger corresponding buffer size, as compared to another contemporaneous link;   determining a higher transmit power value for a link which has a higher priority, as compared to another contemporaneous link;   determining a higher transmit power value for a link having a lower RSRP and/or RSRQ value, as compared to another contemporaneous link.   
     
     
         43 . The method according to any of  claims 38 - 42 , wherein different maximum transmit power values for a link are determined for different subframes and/or for different channels or signals. 
     
     
         44 . The method according to any of  claims 38 - 43 , wherein the maximum transmit power values are determined based on different criteria during different time intervals. 
     
     
         45 . The method according to  claims 43  or  44 , comprising determining a time-varying pattern for the maximum transmit power value for one or more links. 
     
     
         46 . The method according to any of  claims 35 - 45 , wherein the network node is a wireless access point. 
     
     
         47 . The method according to any of the  claims 35 - 46 , wherein the network node is a Main eNB. 
     
     
         48 . The method according to any of  claims 35 - 47 , further comprising determining the actual available power headroom available to the wireless device for transmission on one of the contemporaneous links, based on the received power headroom report and on the obtained maximum transmit power value for that link. 
     
     
         49 . The method according to any of the  claims 35 - 48  wherein the separate maximum transmit power values are determined by the network node. 
     
     
         50 . The method according to any of  claims 35 - 49 , wherein the separate maximum transmit power value for the wireless device per contemporaneous link are received from another network node. 
     
     
         51 . A network node, for enabling transmit power control of a wireless device that is configured to support two or more contemporaneous links with two or more corresponding wireless access points, the network node comprising processing means ( 10 ,  1503 ) and a memory ( 30 ,  1504 ) comprising instructions ( 1505 ), which when executed by the processing means causes the network node ( 1 ,  1500 ) to:
 obtain a separate maximum transmit power value for the wireless device per contemporaneous link, and to   transmit at least one of the obtained maximum transmit power values to another network node, thereby enabling the other network node to control the transmit power of the wireless device for a link corresponding to at least one of the obtained maximum transmit power values.   
     
     
         52 . The network node according to  claim 51 , wherein the execution of the instructions further causes the network node to perform the method according to any of the  claims 2 - 18 . 
     
     
         53 . A network node, for transmit power control of a wireless device that is configured to support two or more contemporaneous links with two or more corresponding wireless access points, the network node comprising processing means ( 10 ,  1503 ) and a memory ( 30 ,  1504 ) comprising instructions ( 1505 ), which when executed by the processing means causes the network node ( 1 ,  1500 ) to:
 obtain a separate maximum transmit power value for the wireless device per contemporaneous link; and to   signal the separate maximum transmit power values to the wireless device.   
     
     
         54 . The network node according to  claim 53 , wherein the execution of the instructions further causes the network node to perform the method according to any of the  claims 20 - 34 . 
     
     
         55 . A network node for scheduling a wireless device, the wireless device being configured to support two or more contemporaneous links with two or more corresponding wireless access points, the network node comprising processing means ( 10 ,  1503 ) and a memory ( 30 ,  1504 ) comprising instructions ( 1505 ), which when executed by the processing means causes the network node ( 1 ,  1500 ) to:
 obtain a separate maximum transmit power value for the wireless device per contemporaneous link;   receive a power headroom report from the wireless device; and   schedule the wireless device on one of the contemporaneous links, based on the obtained maximum transmit power value for that link, and on the received power headroom report.   
     
     
         56 . The network node according to  claim 55 , wherein the execution of the instructions further causes the network node to perform the method according to any of the  claims 36 - 50 . 
     
     
         57 . A method performed in a wireless device configured to support two or more contemporaneous links with two or more corresponding wireless access points, the method comprising:
 receiving ( 1001 ) a separate maximum transmit power value for the wireless device for each contemporaneous link; and   applying ( 1003 ) power control to transmissions on each contemporaneous link based on the maximum transmit power value corresponding to the respective link.   
     
     
         58 . The method according to  claim 57 , further comprising:
 Determining ( 1002 ) that contemporaneous transmission will be performed based on having received more than one uplink grant with respect to a subframe k, and   applying power control to transmissions on each contemporaneous link in subframe k based on the maximum transmit power value corresponding to the respective link.   
     
     
         59 . The method according to  claim 57  or  58 , further comprising receiving an indication to vary one or more of the maximum transmit power values according to a time pattern, and applying power control to transmissions on the corresponding link or links according to the time pattern. 
     
     
         60 . A method performed in a wireless device configured to support two or more contemporaneous links with two or more corresponding wireless access points, the method comprising:
 receiving ( 1101 ) a separate maximum transmit power value for each contemporaneous link, and receiving ( 1102 ) an indication to vary one or more of the maximum transmit power values according to a time pattern   
     
     
         61 . A wireless device configured to support two or more contemporaneous links with two or more corresponding wireless access points, the wireless device comprising processing means ( 1720 ,  1803 ) and a memory ( 1804 ) comprising instructions ( 1805 ), which when executed by the processing means causes the wireless device ( 1700 ,  1800 ) to:
 receive a separate maximum transmit power value for each contemporaneous link, and   apply power control to transmissions on each contemporaneous link based on the maximum transmit power value corresponding to the respective link   
     
     
         62 . The wireless device according to  claim 61 , wherein the execution of the instructions further causes the wireless device to:
 determine that contemporaneous transmission will be performed based on having received more than one uplink grant with respect to a subframe k, and   applying power control to transmissions on each contemporaneous link in subframe k based on the maximum transmit power value corresponding to the respective link.   
     
     
         63 . The wireless device according to  claim 61  or  62 , wherein the execution of the instructions further causes the wireless device to:
 receive an indication to vary one or more of the maximum transmit power values according to a time pattern; and to 
 apply power control to transmissions on the corresponding link or links according to the time pattern. 
 
     
     
         64 . A wireless device configured to support two or more contemporaneous links with two or more corresponding wireless access points, the wireless device comprising processing means ( 1720 ,  1803 ) and a memory ( 1804 ) comprising instructions ( 1805 ), which when executed by the processing means causes the wireless device ( 1700 ,  1800 ) to:
 receive a separate maximum transmit power value for each contemporaneous link, and to receive an indication to vary one or more of the maximum transmit power values according to a time pattern.