# US 11,445,564 B2 · Apparatuses to switch between LTE rat and NR rat during transition from inactive state to active state > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,564 B2 - Document ID: US11445564B2 - Status: Granted - Kind: B2 - Application number: 16/462,342 - Filed: 2017-12-20 - Published: 2019-10-17 - Granted: 2022-09-13 - Earliest claimed: 2016-12-20 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Sudeep Palat; Richard Burbidge; Yujian Zhang; Candy Yiu; Marta Martinez Tarradell; Youn Hyoung Heo; Alexandre Stojanovski; Sangeetha Bangolae - Web page: https://patentgrep.com/patent/US11445564B2 ## CPC - H04W 76/19: Connection re-establishment - H04W 36/0058: {Transmission of hand-off measurement information, e.g. measurement reports} - H04W 36/0055: {Transmission or use of information for re-establishing the radio link} - H04W 48/20: Selecting an access point - H04W 84/042: {Public Land Mobile systems, e.g. cellular systems} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Techniques described herein may be used to enable User Equipment (UE) to switch between Radio Access Technologies (RATs) while transitioning from an inactive state to an active state. For example. a UE may connect to a base station via one type of RAT (e.g., Long-Term Evolution (LTE) RAT), enter an inactive state, and later, while transitioning from the inactive state to an active state, connect to another base station via another type of RAT (e.g., a New Radio (NR) or 5th Generation (5G) RAT). The UE may transition from one RAT to another RAT without increasing signaling between the UE and the network beyond minimal signaling involved in a transition of the UE from the inactive state to an active state. The network may further minimize signaling by determining and communicating minimized connection configuration information to the UE. ## Claims ### Claim 1 An apparatus of a Radio Access Network (RAN) node, the apparatus comprising: an interface to radio frequency (RF) circuitry; and one or more processors to: process, via the interface to the RF circuitry, a request for a User Equipment (UE) to transition from an inactive state to an active state, the request including a UE identity (ID) assigned to the UE by another RAN node, the RAN node corresponding to a first Radio Access Technology (RAT) and the another RAN node corresponding to a second RAT that is different than the first RAT; determine, based on the UE ID, context information including previous connection configuration information, the context information regarding a connection previously established between the UE and the another RAN node; determine, based on the context information from the another RAN node, connection configuration information for establishing a connection between the RAN node and the UE; and cause, via the interface to the RF circuity, the connection configuration information to be communicated to the UE, the communication including a difference in data between the determined connection configuration information and the previous connection configuration information, the communication to enable the UE to transition to the active state and communicate with the RAN node using the connection configuration information. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the first RAT includes New Radio (NR) RAT and the second RAT includes Long-Term Evolution (LTE) RAT. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the first RAT includes Long-Term Evolution (LTE) RAT and the second RAT includes New Radio (NR) RAT. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the RAN node and the another RAN node are connected to a 5th Generation (5G) core network, and the UE ID is associated with the context information for the UE. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein, prior to the UE entering the inactive state, the UE is provided paging area information that includes a first identifier corresponding to the RAN node and a second identifier corresponding to the another RAN node, that the UE may use to roam without incurring any additional signaling. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein, to determine the context information, the one or more processors are to: obtain second RAT context information from the another RAN node by communicating a request for context information, which includes the UE ID, to the another RAN node; and map second RAT context information to the first RAT. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein, to determine the connection configuration information, the one or more processors are to: determine whether to establish a connection with the RAN node that is a duplicate of the connection previously established between the UE and the another RAN node. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the request for the UE to transition from the inactive state to the active state includes security information that corresponds to the connection previously established between the UE and the another RAN node; and wherein the one or more processors are further configured to: cause, via the interface to the RF circuitry, security information to be communicated to the another RAN node; and receive, via the interface to the RF circuitry, a determined authenticity of the UE from the another RAN node, the RAN node choosing to communicate or terminate a connection with the UE based on the determined authenticity. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the one or more processors are to: perform a two-step configuration procedure for communicating with the UE, the two-step configuration procedure including: a first step of activating security for communicating with the UE, and a second step of causing the connection configuration information to be communicated to the UE. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further to: receive, from the another RAN node, a request to page the UE, the request to page the UE including a copy of the UE ID; and cause a paging message, with the copy of the UE ID, to be transmitted to the UE in response to the request to page the UE. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the apparatus stores information indicating a RAT associated with the context information. ### Claim 12 An apparatus of a Radio Access Network (RAN) node, the apparatus comprising: an interface to radio frequency (RF) circuitry; and one or more processors to: process information directed to a User Equipment (UE) that was previously connected to the RAN node during an active state but that has since transitioned to an inactive state; cause, in response to the information directed to the UE, another RAN node to prompt the UE to transition from the inactive state to the active state, the RAN node corresponding to a first Radio Access Technology (RAT) and the another RAN node corresponding to a second RAT that is different than the first RAT; receive, from the another RAN node, a request for context information regarding a connection previously established between the RAN node and the UE, the request including security information and a UE identity (ID) previously assigned to the UE by the RAN node; compare the received security information with other security information previously stored by the RAN node; determine an authenticity of the UE; and provide the context information based on the UE ID to the another RAN node, the context information comprising the determined authenticity of the UE. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the first RAT includes New Radio (NR) RAT and the second RAT includes Long-Term Evolution (LTE) RAT. ### Claim 14 (depends on 12) The apparatus of claim 12, wherein the first RAT includes Long-Term Evolution (LTE) RAT and the second RAT includes New Radio (NR) RAT. ### Claim 15 (depends on 12) The apparatus of claim 12, wherein: the UE ID is used to identify the UE in the second RAT, and to determine the context information, the one or more processors are to: map the UE ID to another UE ID that corresponds to the first RAT and determine the context information based on the another UE ID. ### Claim 16 (depends on 12) The apparatus of claim 12, wherein the RAN node and the another RAN node page the UE to cause the UE to transition from the inactive state to the active state. ### Claim 17 (depends on 12) The apparatus of claim 12, wherein the inactive state includes a mode of operation where the UE does not use a previously established wireless connection but still maintains configuration information for the previously established wireless connection. ### Claim 18 (depends on 12) The apparatus of claim 12, wherein the apparatus stores information indicating a RAT associated with the context information. ### Claim 19 An apparatus of a User Equipment (UE), the apparatus comprising: an interface to radio frequency (RF) circuitry; and one or more processors to: establish, via the interface to the RF circuitry, a wireless connection with a Radio Access Network (RAN) node corresponding to a first Radio Access Technology (RAT); receive, via the interface to the RF circuitry, a UE ID assigned to the UE by the RAN node; transition from an active state to an inactive state; receive, via the interface to the RF circuitry and from another RAN node, a prompt to transition from the inactive state to the active state, the another RAN node corresponding to a second RAT that is different than the first RAT; communicate, via the interface to the RF circuitry and to the another RAN node, a request to establish a connection with the another RAN node, the request including the UE ID; receive, via the interface to the RF circuitry and from the another RAN node, configuration information for establishing the connection with the another RAN node; establish the connection based on the configuration information; and communicate, via the interface to the RF circuitry, with the another RAN node; wherein the UE is configured to communicate with multiple RATs; wherein the apparatus is configured to store context information for each RAT the UE is configured to communicate with. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the first RAT includes New Radio (NR) RAT and the second RAT includes Long-Term Evolution (LTE) RAT. ### Claim 21 (depends on 19) The apparatus of claim 19, wherein the first RAT includes Long-Term Evolution (LTE) RAT and the second RAT includes New Radio (NR) RAT. ### Claim 22 (depends on 19) The apparatus of claim 19, wherein the UE ID is used to identify the UE in the first RAT and the second RAT. ### Claim 23 (depends on 19) The apparatus of claim 19, wherein the UE ID is only used to identify the UE in the first RAT. ### Claim 24 (depends on 19) The apparatus of claim 19, wherein, prior to entering the inactive state, the one or more processors are further to: receive paging area information that includes a first identifier corresponding to the RAN node and a second identifier corresponding to the another RAN node, that the UE may use to roam without incurring any additional signaling. ### Claim 25 (depends on 19) The apparatus of claim 19, wherein the configuration information comprises a difference in data between new connection configuration information and old connection configuration information previously used by the UE; wherein the one or more processors are further to: calculate the new connection configuration information based on the difference in data; establish the connection with the another RAN node based on the new connection configuration information.