Method for inter-RAT reselection decision based on unbalanced radio conditions and device for executing said method
The invention relates to a wireless communication device (UE) configured to be operating in a wireless cellular network supporting a wireless technology standard. For solving the problem of blockage of the UE in regards with one cellular network the UE makes a comparison of communication conditions in downlink and in uplink in order to detect unbalanced communication conditions between downlink and uplink channels and, in case downlink communication conditions are acceptable, but uplink communication conditions show a degradation, initiate an inter-RAT reselection.
1. A method for providing seamless communication of a wireless communication device operating within a wireless cellular network, the method including the steps for the wireless communication device:
registering to a cell of the wireless cellular network by communicating with a network node representing at least said cell,
operating in idle mode,
receiving downlink communication from the network node,
measuring communication conditions of downlink communication,
deciding based on measurement that downlink communication conditions fulfil predefined downlink threshold values,
monitoring at least one parameter relative to uplink communication conditions, said step of monitoring including:
executing attempts of uplink communication,
detecting if the attempts are unsuccessful,
after a predetermined number of unsuccessful attempts of uplink communication, setting the at least one monitored parameter to a value indicating a degradation of uplink communication;
deciding, based on the at least one monitored parameter, that uplink communication conditions do not fulfil predefined uplink threshold values, wherein the step of deciding includes deciding that a value indicating a degradation of uplink communication leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values, and
in such case, initiating an inter-RAT reselection.
2. The method according to claim 1 , wherein the wireless communication device is detecting unsuccessful attempts of uplink communication in case said network node does not reply properly in response to the uplink communication, wherein no proper response comprises at least one of:
reception of a failure message from the network node,
no reception of a response at all from the network node within a predetermined timeframe,
reception of a message from the network node, which is not expected to be received upon the request.
3. The method according to claim 1 , wherein the step of monitoring of at least one parameter relative to uplink communication conditions comprises detection of change of temperature conditions prior to an attempt of uplink communication, the at least one monitored parameter is set to a value indicating the change of temperature conditions,
and wherein the step of deciding based on the monitored parameter comprises that a value indicating a change of temperature conditions in terms of temperature increase leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values.
4. The method according to claim 1 , wherein the step of monitoring of at least one parameter relative to uplink communication conditions comprises detection of reduction of output power of uplink communication, after a reduction of output power the at least one monitored parameter is set to a value indicating the reduction of output power,
and wherein the step of deciding based on the monitored parameter comprises that a value indicating a reduction of output power leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values.
5. The method according to claim 1 , wherein monitoring of at least one parameter relative to uplink communication conditions comprises detection of temperature conditions by way of a prediction of a temperature increase during a scheduled service fulfilment, and the at least one monitored parameter is set to a value indicating one of:
a predicted temperature increase and/or,
a reduction of output power in response to predicted temperature increase,
and wherein the step of deciding based on the monitored parameter comprises that a value indicating a predicted temperature increase or a reduction of output power leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values.
6. The method according to claim 5 , wherein prediction of temperature increase is based on currently required RACH power in comparison to a power required in the wireless technology of the wireless cellular network the wireless communication device is currently operating in for the scheduled service fulfilment.
7. The method according to claim 1 , wherein monitoring of at least one parameter relative to uplink communication conditions comprises executing uplink communication attempts to the network node on certain channels and/or carriers, receiving of response from the network node comprising reporting of received power and comparing used power for said uplink communication attempt and reported received power, the at least one monitored parameter is set to a value indicating a degradation of certain carriers and/or channels of uplink communication if the difference of used power for uplink communication and reported received power exceeds a predetermined threshold,
and wherein the step of deciding based on the monitored parameter comprises that a value indicating a degradation of certain carriers and/or channels leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values.
8. The method according to claim 1 , wherein the inter-RAT cell-reselection is targeting a second wireless cellular network supporting a wireless technology standard which can be operated with lower power consumption than the wireless cellular network, the wireless communication device is currently operating in, and which downlink communication conditions fulfil predefined second downlink threshold values.
9. A wireless communication device, comprising a wireless network communication unit, a monitoring unit, a communication condition judgement unit and a reselection decision unit, wherein the wireless network communication unit is configured to:
register to a cell of wireless cellular network by communicating with a network node representing at least said cell,
operate in idle mode,
receive downlink communication from the network node,
measure communication conditions of downlink communication, the monitoring unit is configured to
monitor at least one parameter relative to uplink communication conditions, including:
execute attempts of uplink communication,
detect if the attempts are unsuccessful, and
after a predetermined number of unsuccessful attempts of uplink communication, set the at least one monitored parameter to a value indicating a degradation of uplink communication,
wherein the communication condition judgement unit is configured to,
decide based on the measurements of wireless network communication unit, if downlink communication conditions fulfil predefined downlink threshold values,
decide, based on the monitored parameter, that a value indicating a degradation of uplink communication leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values, and
wherein the reselection decision unit is configured to:
initiate an inter-RAT reselection in case communication condition judgement unit decided that downlink communication conditions fulfil predefined downlink threshold values and uplink communication conditions do not fulfil predefined uplink threshold values.
10. The wireless communication device according to claim 9 , wherein for detection of an unsuccessful attempt of uplink communication, the wireless communication device is configured to determine that the network node does not reply properly in response to the uplink communication.
11. The wireless communication device according to claim 9 , further comprising a temperature condition sensor, wherein
the temperature condition sensor is configured to detect a change of temperature conditions,
the wireless network communication unit is configured to reduce in response to the detected change of temperature condition the output power of uplink communication, and
set the at least one monitored parameter to a value indicating the reduction of output power, the communication condition judgement unit is configured to decide based on the monitored parameter that a value indicating a reduction of output power leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values.
12. The wireless communication device according to claim 9 , further comprising an temperature prediction unit, wherein
the temperature prediction unit ( 260 ) is configured to predict a temperature increase during a scheduled service fulfilment, and
set the at least one monitored parameter to a value indicating one of:
a predicted temperature increase, and/or
a reduction of output power in response to predicted temperature increase, the communication condition judgement unit is configured to decide based on the monitored parameter that a value indicating a predicted temperature increase or a reduction of output power leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values.
13. The wireless communication device according to claim 9 , wherein the wireless network communication unit is configured to:
execute attempts of uplink communication to the network node on certain channels and/or carriers,
receive response from the network node comprising reporting of received power
compare used power for said uplink communication attempt and reported received power,
if the difference of used power for uplink communication and reported received power exceeds a predetermined threshold, set the at least one monitored parameter to a value indicating a degradation of certain carriers and/or channels of uplink communication, the communication condition judgement unit is configured to decide based on the monitored parameter that a value indicating a degradation of uplink communication leads to the decision that uplink communication conditions do not fulfil predefined uplink threshold values.
14. The wireless communication device according to claim 9 , wherein the reselection decision unit is configured to:
target a second wireless cellular network supporting a wireless technology standard which can be operated with lower power consumption than the wireless cellular network, the wireless communication device is currently operating in, and for which second wireless cellular network the communication condition judgement unit decided based on the measurements of wireless network communication unit, if downlink communication conditions fulfils predefined second downlink threshold values.