Infrastructure equipment, wireless communications network, communication device and methods
A method of operating a communications device to transmit data to or to receive data from a wireless communications network comprises detecting a first synchronisation signal at the communications device received via a wireless access interface of a cell of the wireless communications network, the first synchronisation signal being transmitted with a first periodicity with respect to a time divided structure of the wireless access interface, the first synchronisation signal being configured to carry an indication of an identifier of the cell, generating a first estimate of the cell identifier carried by the first synchronisation signal, and configuring a transmitter of the communications device to transmit data to the wireless communications network and configuring a receiver of the communications device to receive data from the wireless communications network based on the first estimated cell identifier.
1. A method of operating an infrastructure equipment in a wireless communications network, the method comprising:
providing a wireless access interface by the infrastructure equipment to form a cell of the wireless communications network, the infrastructure equipment forming part of a radio access network of the wireless communications network,
transmitting system information by the infrastructure equipment periodically via the wireless access interface to communication devices in accordance with a time divided structure of the wireless access interface, the system information being used for use by the communications devices to configure a transmitter or a receiver of the communications devices to transmit data to or to receive data from the wireless interface provided by the infrastructure equipment,
transmitting with a first periodicity with respect to the time divided structure of the wireless access interface a first synchronisation signal to the communications devices within the cell formed by the infrastructure equipment, the first synchronisation signal being configured to carry a first indication of a Physical Cell Identifier (PCID) of the cell which is detectable by one or more communications devices for acquiring synchronisation with the time divided structure of the wireless access interface, and
transmitting with a second periodicity with respect to the time divided structure of the wireless access interface an enhanced synchronisation signal within the cell, the enhanced synchronisation signal being configured to carry a second indication of the PCID of the cell or one or more other signalling indications for the communications devices and is detectable by the communications devices for acquiring synchronisation with the time divided structure of the wireless access interface, wherein
the second periodicity is less than the first periodicity,
the enhanced synchronisation signal is transmitted more frequently than the first synchronisation signal whereby the communications devices are re-synchronisable in shorter time than a time to acquire synchronisation with respect to the first synchronisation signal,
the enhanced synchronisation signal is formed from one of a set of detectable sequences, each detectable sequence of the set representing one of a set of possible PCIDs or the one or more other signalling indications for the communications devices, and
when the one or more other signalling indications for the communications devices provided by one or more of the detectable sequences of the set are transmitted, the one or more other signalling indications includes an indication as to whether or not the system information has changed with respect to a previous transmission of the system information.
2. A method as claimed in claim 1 ,
wherein the enhanced synchronisation signal is configured to carry the one or more other signalling indications for the communications devices, and
wherein the transmitting the system information by the infrastructure equipment periodically via the wireless access interface comprises transmitting a master information block and transmitting one or more other system information blocks each providing different types of the system information for the communications devices, and the one or more other signalling indications for the communications devices, when transmitted, include an indication as to whether or not at least one of the system information transmitted in the master information block or the system information transmitted in one or more of the other system information blocks has changed with respect to a previous transmission of the system information.
3. A method as claimed in claim 1 ,
wherein the enhanced synchronisation signal is configured to carry the one or more of signalling indications for the communications devices, and
wherein the one or more other signalling indications for the communications devices provided by one or more of the detectable sequences of the set, when transmitted, includes an indication relating a configuration of wake-up signals, the indication indicating to the communications devices that one or more of the communications devices should detect one or more paging signals in one or more paging occasions of a paging timing window.
4. A method as claimed in claim 1 ,
wherein the enhanced synchronisation signal is configured to carry the one or more other signalling indications for the communications devices, and
wherein the one or more other signalling indications for the communications devices provided by one or more of the detectable sequences of the set, when transmitted, includes an indication of an access class bar representing a class of the communications devices which is barred from performing a random access procedure including transmitting a random access preamble to the infrastructure equipment.
5. A method as claimed in claim 1 , wherein the transmitting with the second periodicity with respect to the time divided structure the enhanced synchronisation signal to the communications devices within the cell includes transmitting a plurality of different versions of the enhanced synchronisation signal, each version of the enhanced synchronisation signal being formed from a different sub-set of the set of detectable sequences, each of the different sub-sets of the detectable sequences including detectable sequences representing a sub-set of possible PCIDs, and each of the different sub-sets of the detectable sequences including detectable sequences representing at least one of the one or more other signalling indications which is different to the other sub-sets.
6. A method as claimed in claim 5 , wherein the transmitting the plurality of different versions of the enhanced synchronisation signal includes transmitting each version of the enhanced synchronisation signal with a different number of times within the second periodicity.
7. A method as claimed in claim 6 , wherein the different number of times of transmission of the different versions of the enhanced synchronisation sequence corresponds to a likelihood of the different at least one of the one or more other signalling indication changing with respect to a previous transmission.
8. A method as claimed in claim 1 , wherein the second periodicity with which the enhanced synchronisation signal is transmitted is configurable by the infrastructure equipment.
9. An infrastructure equipment for forming part of a radio access network of a wireless communications network, the infrastructure equipment comprising:
transmitter circuitry configured to transmit signals via a wireless access interface of a cell of the wireless communications network formed by the infrastructure equipment,
receiver circuitry configured to receive signals transmitted via the wireless access interface of the cell formed by the infrastructure equipment, and
controller circuitry configured to control the transmitter
to transmit system information periodically via the wireless access interface to communication devices in accordance with a time divided structure of the wireless access interface, the system information being used for use by one or more communications devices to configure a transmitter or a receiver of each of the one or more communications devices to transmit data to or to receive data from the wireless access interface provided by the infrastructure equipment,
to transmit with a first periodicity with respect to the time divided structure of the wireless access interface a first synchronisation signal to the communications devices within the cell formed by the infrastructure equipment, the first synchronisation signal being configured to carry a first indication of a Physical Cell Identifier (PCID) of the cell which is detectable by the communications devices for acquiring synchronisation with the time divided structure of the wireless access interface, and
to transmit with a second periodicity with respect to the time divided structure of the wireless access interface an enhanced synchronisation signal to the communications devices within the cell, the enhanced synchronisation signal being configured to carry a second indication of the PCID of the cell or one or more other signalling indications for the communications devices and is detectable by the communications devices for acquiring synchronisation with the time divided structure of the wireless access interface, wherein
the second periodicity is less than the first periodicity,
the enhanced synchronisation signal is transmitted more frequently than the first synchronisation signal whereby the communications devices are re-synchronisable in shorter time than a time to acquire synchronisation with respect to the first synchronisation signal,
the enhanced synchronisation signal is formed from one of a set of detectable sequences, each detectable sequence of the set representing one of a set of possible PCIDs or the one or more other signalling indications for the communications devices, and
when the one or more other signalling indications for the communications devices provided by one or more of the detectable sequences of the set are transmitted, the one or more other signalling, indications includes an indication as to whether or not the system information has changed with respect to a previous transmission of the system information.
10. An infrastructure equipment as claimed in claim 9 ,
wherein the enhanced synchronisation signal is configured to carry the one or more other signalling indications for the communications devices, and
wherein the transmitting the system information by the infrastructure equipment periodically via the wireless access interface comprises transmitting a master information block and transmitting one or more other system information blocks each providing different types of the system information for the communications devices, and the one or more other signalling indications for the communications devices, when transmitted, include an indication as to whether or not at least one of the system information transmitted in the master information block or the system information transmitted in one or more of the other system information blocks has changed with respect to a previous transmission of the system information.
11. An infrastructure equipment as claimed in claim 9 ,
wherein the enhanced synchronisation signal is configured to carry the one or more other signalling indications for the communications devices, and
wherein the one or more other signalling indications for the communications devices provided by one or more of the detectable sequences of the set, when transmitted, includes an indication relating a configuration of wake-up signals, the indication indicating to the communications devices that one or more of the communications devices should detect one or more paging signals in one or more paging occasions of a paging timing window.
12. An infrastructure equipment as claimed in claim 9 ,
wherein the enhanced synchronisation signal is configured to carry the one or more other signalling indications for the communications devices, and
wherein the one or more other signalling indications for the communications devices provided by one or more of the detectable sequences of the set, when transmitted, includes an indication of an access class bar representing a class of the communications devices which is barred from performing a random access procedure including transmitting a random access preamble to the infrastructure equipment.
13. An infrastructure equipment as claimed in claim 9 , wherein the transmitting with the second periodicity with respect to the time divided structure the enhanced synchronisation signal to the communications devices within the cell includes transmitting a plurality of different versions of the enhanced synchronisation signal, each version of the enhanced synchronisation signal being formed from a different sub-set of the set of detectable sequences, each of the different sub-sets of the detectable sequences including detectable sequences representing a sub-set of possible PCIDs, and each of the different sub-sets of the detectable sequences including detectable sequences representing at least one of the one or more other signalling indications which is different to the other sub-sets.
14. An infrastructure equipment as claimed in claim 13 , wherein the transmitting the plurality of different versions of the enhanced synchronisation signal includes transmitting each version of the enhanced synchronisation signal with a different number of times within the second periodicity.
15. An infrastructure equipment as claimed in claim 14 , wherein the different number of times of transmission of the different versions of the enhanced synchronisation sequence corresponds to a likelihood of the different at least one of the one or more other signalling indication changing with respect to a previous transmission.
16. An infrastructure equipment as claimed in claim 9 , wherein the second periodicity with which the enhanced synchronisation signal is transmitted is configurable by the infrastructure equipment.