# US 2018/0323908 A1 · System information transmission method and wireless communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323908 A1 - Document ID: US20180323908A1 - Status: Published application - Kind: A1 - Application number: 15/969,785 - Filed: 2018-05-03 - Published: 2018-11-08 - Earliest claimed: 2017-05-05 - Assignees: Hannibal IP LLC - Inventors: CHIE-MING CHOU - Web page: https://patentgrep.com/patent/US20180323908A1 ## CPC - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04L 1/1671: {the supervisory signal being transmitted together with control information} - H04L 1/1887: {Scheduling and prioritising arrangements} - H04W 48/14: using user query {or user detection} - H04W 72/04: Wireless resource allocation - H04L 2101/622: Layer-2 addresses, e.g. medium access control [MAC] addresses - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 88/02: Terminal devices - H04W 88/08: Access point devices - 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 system information transmission method is provided. The system information transmission method includes the following steps. A first preamble for system information request is transmitted by a UE to a base station. When an acknowledgement message from the base station is not received, the first preamble for system information request is retransmitted by the UE to the base station. When the acknowledgement message from the base station is received, system information is received by the UE from the base station. ## Claims ### Claim 1 A system information transmission method, comprising: transmitting, by a user equipment (UE), a first preamble for system information request to a base station; retransmitting, by the UE, the first preamble for system information request to the base station when an acknowledgement message from the base station is not received; and receiving, by the UE, system information from the base station when the acknowledgement message from the base station is received. ### Claim 2 (depends on 1) The system information transmission method of claim 1, further comprising: retransmitting, by the UE, the first preamble for system information request to the base station when the acknowledgement message from the base station is received and the acknowledgement message does not correspond to the first preamble for system information request. ### Claim 3 (depends on 1) The system information transmission method of claim 1, wherein the UE includes a timer, and the step of retransmitting the first preamble for system information request to the base station is performed when the timer expires. ### Claim 4 (depends on 1) The system information transmission method of claim 1, wherein the UE includes a counter, and the system information transmission method further comprises: counting, by the counter, a number of retransmitting the first preamble for system information request to the base station; wherein when the number of retransmitting the first preamble for system information request to the base station exceeds a threshold; transmitting, by the UE, a second preamble for random access to the base station; receiving, by the UE, a random access response from the base station; and transmitting, by the UE, a system information request when the random access response is received. ### Claim 5 (depends on 2) The system information transmission method of claim 2, wherein the acknowledgement message corresponding to the first preamble for system information request is a random access response including only cell radio network temporary identifier. ### Claim 6 (depends on 2) The system information transmission of claim 2, wherein the acknowledgement message corresponding to the first preamble for system information request is a MAC subheader including only random access preamble identifier. ### Claim 7 (depends on 1) The system information transmission method of claim 1, wherein the system information is received in a pre-defined system information window. ### Claim 8 (depends on 1) The system information transmission method of claim 1, wherein the system information is included in the acknowledgement message, and the acknowledgement message includes a flag indicating that the system information is appended. ### Claim 9 (depends on 1) The system information transmission method of claim 1, wherein the acknowledgement message includes a resource allocation and a flag indicating that the system information is not appended, and the system information is received in response to the resource allocation. ### Claim 10 A user equipment (UE), comprising: a processor configured to perform instructions for: transmitting a first preamble for system information request to a base station; retransmitting, by the UE, the first preamble for system information request to the base station when an acknowledgement message from the base station is not received; and receiving system information from the base station when the acknowledgement message from the base station is received. ### Claim 11 (depends on 10) The UE of claim 10, wherein the processor is further configured to perform instructions for: retransmitting the first preamble for system information request to the base station when the acknowledgement message from the base station is received and the acknowledgement message does not correspond to the first preamble for system information request. ### Claim 12 (depends on 10) The UE of claim 10, further includes: a timer configured for starting at a time when the first preamble for system information request is transmitted, wherein the processor is configured for retransmitting the first preamble for system information request to the base station when the timer expires. ### Claim 13 (depends on 10) The UE of claim 10, further includes: a counter configured for counting a number of retransmitting the first preamble for system information request to the base station; wherein when the number of retransmitting the first preamble for system information request to the base station exceeds a threshold, the processor is configured to perform instructions for: transmitting a second preamble for random access to the base station; receiving a random access response from the base station; and transmitting a system information request when the random access response is received. ### Claim 14 (depends on 11) The UE of claim 11, wherein the acknowledgement message corresponding to the first preamble for system information request is a random access response including only cell radio network temporary identifier. ### Claim 15 (depends on 11) The UE of claim 11, wherein the acknowledgement message corresponding to the first preamble for system information request is a MAC subheader including only random access preamble identifier. ### Claim 16 (depends on 10) The UE of claim 10, wherein the system information is received in a pre-defined system information window. ### Claim 17 (depends on 10) The UE of claim 10, wherein the system information is included in the acknowledgement message, and the acknowledgement message includes a flag indicating that the system information is appended. ### Claim 18 (depends on 10) The UE of claim 10, wherein the acknowledgement message includes a resource allocation and a flag indicating that the system information is not appended, and the system information is received in response to the resource allocation. ### Claim 19 A base station, comprising: a processor configured to perform instructions for: receiving a system information request from a user equipment (UE); transmitting an acknowledgement message to the UE when the system information request included in a first preamble for system information request is received; transmitting system information to the UE. ### Claim 20 (depends on 19) The base station of claim 19, wherein the system information is broadcasted by the processor in a pre-defined system information window. ### Claim 21 (depends on 19) The base station of claim 19, wherein the system information is included in the acknowledgement message and a flag of the acknowledgement message indicates that the system information is appended. ### Claim 22 (depends on 19) The base station of claim 19, wherein the acknowledgement message includes a resource allocation and a flag indicating that system information is not appended, and the system information is transmitted in response to the resource allocation. ### Claim 23 (depends on 19) The base station of claim 19, wherein the acknowledgement message is a random access response including only cell radio network temporary identifier. ### Claim 24 (depends on 19) The base station of claim 19, wherein the acknowledgement message is a MAC subheader including only random access preamble identifier. ### Claim 25 (depends on 19) The base station of claim 19, wherein the processor is further configured to perform instructions for: receiving a second preamble for random access from the UE; transmitting a random access response to the UE; wherein the system information request is received after the random access response is transmitted. ### Claim 26 A system information transmission method, comprising: receiving, by a base station, a system information request from a user equipment (UE); transmitting, by the base station, an acknowledgement message to the UE when the system information request included in a first preamble for system information request is received; transmitting, by the base station, system information to the UE. ### Claim 27 (depends on 26) The system information transmission method of claim 26, wherein the system information is broadcasted by the base station in a pre-defined system information window. ### Claim 28 (depends on 26) The system information transmission method of claim 26, wherein the system information is included in the acknowledgement message and a flag of the acknowledgement message indicates that the system information is appended. ### Claim 29 (depends on 26) The system information transmission method of claim 26, wherein the acknowledgement message includes a resource allocation and a flag indicating that system information is not appended, and the system information is transmitted in response to the resource allocation. ### Claim 30 (depends on 26) The system information transmission method of claim 26, wherein the acknowledgement message is a random access response including only cell radio network temporary identifier. ### Claim 31 (depends on 26) The system information transmission method of claim 26, wherein the acknowledgement message is a MAC subheader including only random access preamble identifier. ### Claim 32 (depends on 26) The system information transmission method of claim 26, further comprising: receiving, by the base station, a second preamble for random access from the UE; transmitting, by the base station, a random access response to the UE; wherein the system information request is received after the random access response is transmitted.