Multi-Carrier Operation for Narrowband Internet of Things
A novel and efficient multi-carrier operation mechanism is proposed to maintain the capacity and reliability for NB-IOT systems. First, the functional separation on anchor NB-IOT carrier and data NB-IOT carriers is defined. Transportation of system broadcast information, including synchronization signal (NB-PSS/NB-SSS) and NB-MIB (NB-PBCH) and paging are on anchor carrier, RACH procedure and Data transmission and reception are on data carrier. Second, UE switching between anchor and data carriers. UE on anchor carrier switches to data carrier via paging, RRC signaling or cross-carrier scheduling. On the other hand, UE on data carrier switches back to anchor carrier after transmission or reception complete (right-after or after time-out).
1 . A method comprising:
receiving control and reference information from a base station by a user equipment (UE) over an anchor carrier, wherein the UE supports multicarrier operation over the anchor carrier and a plurality of non-anchor carriers;
selecting a data carrier from the plurality of non-anchor carriers and switching to the data carrier upon receiving a paging message;
performing a random-access channel (RACH) procedure with a base station over the selected data carrier; and
establishing a radio resource control (RRC) connection and performing a data exchange with the base station over the selected data carrier.
2 . The method of claim 1 , wherein the data carrier is selected autonomously by the UE.
3 . The method of claim 2 , wherein the data carrier is selected based on the control and reference information received by the UE over the anchor carrier.
4 . The method of claim 2 , wherein the data carrier is selected based on at least one of a UE identity, a service identity, a network slice identity, a QoS identifier, and a radio coverage of the data carrier.
5 . The method of claim 1 , wherein the data carrier is selected based on carrier assignment information received from the base station.
6 . The method of claim 5 , wherein the carrier assignment information is received via the paging message on the anchor carrier.
7 . The method of claim 5 , wherein the carrier assignment information is received via an RRC signaling on the anchor carrier.
8 . The method of claim 1 , further comprising:
starting a timer upon completing the data exchange; and
switching back to the anchor carrier when the timer expires.
9 . A user equipment (UE) comprising:
a radio frequency (RF) receiver that receives control and reference information from a base station by the UE over an anchor carrier, wherein the UE supports multicarrier operation over the anchor carrier and a plurality of non-anchor carriers;
a carrier selection circuit that selects a data carrier from the plurality of non-anchor carriers and switching to the data carrier upon receiving a paging message;
a random-access circuit that performs a random-access channel (RACH) procedure with a base station over the selected data carrier; and
a radio resource control (RRC) circuit that establishes an RRC connection and performs a data exchange with the base station over the selected data carrier.
10 . The UE of claim 9 , wherein the data carrier is selected autonomously by the UE.
11 . The UE of claim 10 , wherein the data carrier is selected based on the control and reference information received by the UE over the anchor carrier.
12 . The UE of claim 10 , wherein the data carrier is selected based on at least one of a UE identity, a service identity, a network slice identity, a QoS identifier, and a radio coverage of the data carrier.
13 . The UE of claim 9 , wherein the data carrier is selected based on carrier assignment information received from the base station.
14 . The UE of claim 13 , wherein the carrier assignment information is received via the paging message on the anchor carrier.
15 . The UE of claim 13 , wherein the carrier assignment information is received via an RRC signaling on the anchor carrier.
16 . The method of claim 1 , wherein the UE starts a timer upon completing the data exchange, and the UE switches back to the anchor carrier when the timer expires.
17 . A method, comprising:
receiving control and reference information from a base station by a user equipment (UE) over an anchor carrier, wherein the UE supports multicarrier operation over the anchor carrier and a plurality of non-anchor carriers;
monitoring a physical downlink control channel (PDCCH) on the anchor carrier and receiving downlink control information (DCI);
switching to a selected data carrier from the plurality of non-anchor carriers based on the DCI received on the anchor carrier; and
establishing a radio resource control (RRC) connection and performing a data exchange with the base station over the selected data carrier.
18 . The method of claim 17 , further comprising:
switching back to the anchor carrier when the data exchange is completed.
19 . The method of claim 17 , further comprising:
switching back to the anchor carrier as indicated by the DCI received on the anchor carrier.
20 . The method of claim 17 , wherein there is a non-scheduling period between receiving the DCI on the anchor carrier and the data exchange on the selected data carrier.