# US 10,313,076 B2 · Wireless communication device, network node, methods and computer programs for aiding finding of synchronisation signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,313,076 B2 - Document ID: US10313076B2 - Status: Granted - Kind: B2 - Application number: 15/604,136 - Filed: 2017-05-24 - Published: 2018-11-08 - Granted: 2019-06-04 - Earliest claimed: 2017-05-04 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Bengt Lindoff; Peter Alriksson; Magnus Astrom - Web page: https://patentgrep.com/patent/US10313076B2 ## CPC - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04W 16/14: Spectrum sharing arrangements {between different networks} - H04W 36/00: Hand-off or reselection arrangements - H04W 36/0066: {of control information between different types of networks in order to establish a new radio link in the target network} - H04W 56/001: {Synchronization between nodes} - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 36/0072: {of resource information of target access point} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method of a network node of a cellular communication system for mobility from a first radio access network, RAN, operating using a first radio access technology, RAT, to a second RAN operating using a second RAT. The first RAT has synchronization signals with a first frequency allocation and the second RAT has synchronization signals with a second frequency allocation in relation to a network frequency for the second RAT. The method comprises determining allocation information about the synchronization signals of the second RAT, and transmitting a radio resource control, RRC, message including the allocation information about the synchronization signals of the second RAT. A method for the wireless communication device is also disclosed, as well as a network node, a wireless communication device and computer programs for them. ## Claims ### Claim 1 A method of a wireless communication device of a cellular communication system for mobility from a first radio access network, RAN, operating using a first radio access technology, RAT, to a second RAN operating using a second RAT, wherein the first RAT has synchronisation signals with a first frequency allocation and the second RAT has synchronisation signals with a second frequency allocation in relation to a network frequency for the second RAT, the method comprising: receiving a radio resource control, RRC, message including allocation information about the synchronisation signals of the second RAT; and performing synchronisation signal detection based on the allocation information. ### Claim 2 (depends on 1) The method of claim 1, wherein the allocation information comprises specific frequency information for the synchronisation signals. ### Claim 3 (depends on 1) The method of claim 1, wherein the allocation information comprises a frequency offset for the synchronisation signal frequency in relation to the network frequency. ### Claim 4 (depends on 1) The method of claim 1, wherein the performing synchronisation signal detection comprises: changing receiver frequency based on the frequency allocation of the synchronisation signals such that synchronisation signals are comprised in a received bandwidth; monitoring within the received bandwidth for synchronisation signals; and decoding, upon found synchronisation signals, the synchronisation signals. ### Claim 5 (depends on 1) The method of claim 1, comprising, after performing synchronisation signal detection, tuning the receiver frequency to the determined network frequency. ### Claim 6 (depends on 1) The method of claim 1, further comprising: determining, upon successful synchronisation, allocation information about the synchronisation signals of the RAT on which the successful synchronisation has been performed; and transmitting, to the network node or neighbouring network nodes of the network node, information about the RAT on which the successful synchronisation has been performed including the information about the allocation information of the synchronisation signals of the RAT on which the successful synchronisation has been performed. ### Claim 7 A wireless communication device arranged to operate in a cellular communication system and capable of mobility from a first radio access network, RAN, operating using a first radio access technology, RAT, to a second RAN operating using a second RAT, wherein the first RAT has synchronisation signals with a first allocation and the second RAT has synchronisation signals with a second frequency allocation in relation to a network frequency for the second RAT, the wireless communication device comprising: a transceiver; and a controller, wherein the transceiver is arranged to receive a radio resource control, RRC, message including allocation information about the synchronisation signals of the second RAT, and the controller is arranged to cause the transceiver to perform synchronisation signal detection based on the allocation information. ### Claim 8 (depends on 7) The wireless communication device of claim 7, wherein the allocation information comprises specific frequency information for the synchronisation signals. ### Claim 9 (depends on 7) The wireless communication device of claim 7, wherein the allocation information comprises a frequency offset for the synchronisation signal frequency in relation to the network frequency. ### Claim 10 (depends on 7) The wireless communication device of claim 7, arranged to perform the synchronisation signal detection by being arranged to: change receiver frequency of the transceiver based on the frequency allocation of the synchronisation signals such that synchronisation signals are comprised in a received bandwidth; monitor within the received bandwidth for synchronisation signals; and decode, upon found synchronisation signals, remaining synchronisation signals of a system network access signalling transmission. ### Claim 11 (depends on 7) The wireless communication device of claim 7, arranged to, after performing synchronisation signal detection, tune the receiver frequency of the transceiver to the determined network frequency. ### Claim 12 (depends on 7) The wireless communication device of claim 7, further being arranged to: determine, upon successful synchronisation, allocation information about the synchronisation signals of the RAT on which the successful synchronisation has been performed; and transmit, to neighbouring network nodes of the network node, information about the RAT on which the successful synchronisation has been performed including the information about the allocation information of the synchronisation signals of the RAT on which the successful synchronisation has been performed. ### Claim 13 A method of a network node of a cellular communication system for mobility from a first radio access network, RAN, operating using a first radio access technology, RAT, to a second RAN operating using a second RAT, wherein the first RAT has synchronisation signals with a first frequency allocation and the second RAT has synchronisation signals with a second frequency allocation in relation to a network frequency for the second RAT, the method comprising: determining allocation information about the synchronisation signals of the second RAT; and transmitting a radio resource control, RRC, message including the allocation information about the synchronisation signals of the second RAT. ### Claim 14 (depends on 13) The method of claim 13, wherein the allocation information comprises specific frequency information for the synchronisation signals. ### Claim 15 (depends on 13) The method of claim 13, wherein the determining of the allocation information about the synchronisation signals of the second RAT comprises: receiving through signalling from the cellular communication system information about the second RAT; and extracting information about the allocation information of the synchronisation signals of the second RAT from the information about the second RAT. ### Claim 16 (depends on 13) The method of claim 13, wherein the determining of the allocation information about the synchronisation signals of the second RAT comprises: estimating likely allocation information about the synchronisation signals of the second RAT. ### Claim 17 (depends on 13) The method of claim 13, wherein the determining of the allocation information about the synchronisation signals of the second RAT comprises: acquiring through signalling, from other wireless devices operating in the cellular communication network, information about the second RAT; and extracting information about the allocation information of the synchronisation signals of the second RAT from the information about the second RAT. ### Claim 18 A network node arranged to operate in a cellular communication system and capable of assisting handover from a first radio access technology, RAT, to a second RAT, wherein the second RAT has synchronisation signals with a frequency allocation in relation to a network frequency for the second RAT, the network node comprising: a transceiver; and a controller, wherein the controller is arranged to determine allocation information about the synchronisation signals of the second RAT, and the transceiver is arranged to transmit a radio resource control, RRC, message including the allocation information about the synchronisation signals of the second RAT. ### Claim 19 (depends on 18) The network node of claim 18, wherein the allocation information comprises specific carrier frequency of the synchronisation signals. ### Claim 20 (depends on 18) The network node of claim 18, wherein the allocation information comprises a frequency offset for carrier frequency of the synchronisation signal in relation to the network frequency. ### Claim 21 (depends on 18) The network node of claim 18, wherein: the network node includes an interface that is arranged to receive, through signalling from the cellular communication system, information about the second RAT, and the controller is arranged to extract information about the allocation information of the synchronisation signals of the second RAT from the information about the second RAT. ### Claim 22 (depends on 18) The network node of claim 18, wherein: the controller is arranged to estimate likely allocation information about the synchronisation signals of the second RAT. ### Claim 23 (depends on 18) The network node of claim 18, wherein: the transceiver is arranged to acquire, through signalling from other wireless devices operating in the cellular communication network, information about the second RAT, and the controller is arranged to extract information about the allocation information of the synchronisation signals of the second RAT from the information about the second RAT. ### Claim 24 A nontransitory computer readable storage medium comprising a computer program comprising instructions which, when executed on a processor of a wireless communication device of a cellular communication system, causes the wireless communication device to perform a method for mobility from a first radio access network, RAN, operating using a first radio access technology, RAT, to a second RAN operating using a second RAT, wherein the first RAT has synchronisation signals with a first frequency allocation and the second RAT has synchronisation signals with a second frequency allocation in relation to a network frequency for the second RAT, the method comprising: receiving a radio resource control, RRC, message including allocation information about the synchronisation signals of the second RAT; and performing synchronisation signal detection based on the allocation information. ### Claim 25 A nontransitory computer readable storage medium comprising a computer program comprising instructions which, when executed on a processor of a network node of a cellular communication system, causes the network node to perform a method for mobility from a first radio access network, RAN, operating using a first radio access technology, RAT, to a second RAN operating using a second RAT, wherein the first RAT has synchronisation signals with a first frequency allocation and the second RAT has synchronisation signals with a second frequency allocation in relation to a network frequency for the second RAT, the method comprising: determining allocation information about the synchronisation signals of the second RAT; and transmitting a radio resource control, RRC, message including the allocation information about the synchronisation signals of the second RAT.