Inter-Band Handover of the Same Physical Frequency

Abstract

A method of an access network node of a carrier aggregation enabled cellular wireless communication system, and a method of a wireless terminal device of a carrier aggregation enabled cellular wireless communication system are disclosed. The method for the network node comprises identifying a need for an inter-band handover where a same physical frequency on which the access network node interacts with a wireless terminal device has more than one logical reference, wherein the wireless terminal device currently operates using a first logical reference, assigning a target frequency for the inter-band handover as a second logical reference for the physical frequency, and performing handover signalling with the wireless terminal device including the assigned target frequency. The method of the wireless terminal device comprises performing operation where a need for an inter-band handover occurs where a same physical frequency on which the wireless terminal device interacts with an access network node of the cellular wireless communication system has more than one logical reference, wherein the wireless terminal device currently operates using a first logical reference, and performing handover signalling with the access network node including receiving an assigned target frequency which is a second logical reference for the physical frequency. A network node, a wireless terminal device and computer programs for these for implementing the methods are also disclosed.

1 . A method of operating an access network node of a carrier aggregation enabled cellular wireless communication system, wherein the network node interacts with a wireless terminal device having more than one logical reference on a same physical frequency, wherein the wireless terminal device currently operates using a first logical reference, the method comprising the network node:
 assigning a target frequency for the inter-band handover as a second logical reference for the physical frequency; and   performing handover signaling with the wireless terminal device including the assigned target frequency.   
     
     
         2 . The method of  claim 1 , wherein the logical references are evolved UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access (EUTRA) Absolute Radio-Frequency Channel Number (EARFCN). 
     
     
         3 . The method of  claim 1 , wherein the performing the handover signaling comprises sending a measurement configuration to the wireless terminal device including the second logical reference. 
     
     
         4 . The method of  claim 1 , further comprising performing the handover such that the wireless terminal device operates on the physical frequency using the second logical reference after the handover. 
     
     
         5 . A network node of an access network of a carrier aggregation enabled cellular wireless communication system, wherein the network node interacts with a wireless terminal device having more than one logical reference on a same physical frequency, wherein the wireless terminal device currently operates using a first logical reference, the network node comprising:
 processing circuitry;   memory containing instructions executable by the processing circuitry whereby the network node is operative to:
 assign the target frequency for the inter-band handover as a second logical reference for the physical frequency; and 
 perform handover signaling with the wireless terminal device including the assigned target frequency. 
   
     
     
         6 . The network node of  claim 5 , wherein the logical references are evolved UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access (EUTRA) Absolute Radio-Frequency Channel Number (EARFCN). 
     
     
         7 . The network node of  claim 5 , wherein the handover signaling comprises a measurement configuration transmission to the wireless terminal device including the second logical reference. 
     
     
         8 . The network node of  claim 5 , wherein the instructions are such that the network node is operative to perform the handover such that the wireless terminal device operates on the physical frequency using the second logical reference after the handover. 
     
     
         9 . A method of operating a wireless terminal device of a carrier aggregation enabled cellular wireless communication system, where a same physical frequency on which the wireless terminal device interacts with an access network node of the cellular wireless communication system has more than one logical reference, the method comprising the wireless terminal device:
 performing an operation where a need for an inter-band handover occurs, wherein the wireless terminal device currently operates using a first logical reference; and   performing handover signaling with the access network node including receiving an assigned target frequency which is a second logical reference for the physical frequency.   
     
     
         10 . The method of  claim 9 , further comprising the wireless terminal device:
 analyzing mapping of the first and second logical references to observe that they relate to the same physical frequency; and   in response to observing that they relate to the same physical frequency, recovering measurement values made for the first logical reference and assigning the measurement values for the second logical reference.   
     
     
         11 . The method of  claim 9 , wherein the logical references are evolved UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access (EUTRA) Absolute Radio-Frequency Channel Number (EARFCN). 
     
     
         12 . The method of  claim 9 , wherein the performing handover signaling comprises receiving a measurement configuration including the second logical reference. 
     
     
         13 . The method of  claim 9 , further comprising the wireless terminal device performing the handover such that the wireless terminal device operates on the physical frequency using the second logical reference after the handover. 
     
     
         14 . A wireless terminal device of a carrier aggregation enabled cellular wireless communication system, where a same physical frequency on which the wireless terminal device interacts with an access network node of the cellular wireless communication system has more than one logical reference, the wireless terminal device comprising:
 processing circuitry;   memory containing instructions executable by the processing circuitry whereby the wireless terminal device is operative to:
 perform an operation where a need for an inter-band handover occurs, wherein the wireless terminal device currently operates using a first logical reference; and 
 perform handover signaling with the access network node including receiving an assigned target frequency which is a second logical reference for the physical frequency. 
   
     
     
         15 . The wireless terminal device of  claim 14 , wherein the instructions are such that the wireless terminal device is operative to:
 analyze mapping of the first and second logical references to observe that they relate to the same physical frequency; and   in response to observing that they relate to the same physical frequency, recover measurement values made for the first logical reference and assign the measurement values for the second logical reference.   
     
     
         16 . The wireless terminal device of  claim 14 , wherein the logical references are evolved UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access (EUTRA) Absolute Radio-Frequency Channel Number (EARFCN). 
     
     
         17 . The wireless terminal device of  claim 14 , wherein the performing the handover signaling includes receiving a measurement configuration including the second logical reference. 
     
     
         18 . The wireless terminal device of  claim 14 , wherein the instructions are such that the wireless terminal device is operative perform the handover is such that the wireless terminal operates on the physical frequency using the second logical reference after the handover.