# US 2015/0312798 A1 · Overload control in a communication network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0312798 A1 - Document ID: US20150312798A1 - Status: Published application - Kind: A1 - Application number: 14/648,450 - Filed: 2012-12-04 - Published: 2015-10-29 - Earliest claimed: 2012-12-04 - Assignees: Telefonaktiebolaget L M Ericsson (publ) - Applicants: Telefonaktiebolaget L M Ericsson (publ) - Inventors: Johan RUNE - Web page: https://patentgrep.com/patent/US20150312798A1 ## CPC - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04L 1/0072: {Error control for data other than payload data, e.g. control data} - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04W 28/02: Traffic management, e.g. flow control or congestion control - H04W 28/0289: {Congestion control (load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12)} - H04W 72/12: Wireless traffic scheduling - H04W 74/002: {Transmission of channel access control information} - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 72/00: Local resource management - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Disclosed are methods as well radio network nodes and user equipments (UE) that are suitable for overload control in a communication network. A radio network node may, upon receiving a random access preamble from a UE, determine whether there exists a condition indicative of the radio network node having insufficient resources to respond properly to all random access preambles received by the radio network node. Also, in response to a determination that such condition exists, the radio network node may include in a MAC PDU, a request to extend the time period during which the UE waits for reception of a MAC RAR response. The radio network node may also transmit this MAC PDU including this request to the UE. ## Claims ### Claim 1 A method performed by a radio network node for overload control in a communication network, the method comprising: receiving a random access preamble from an unserved user equipment, UE; upon receiving the random access preamble, determining whether a condition indicative of the radio network node having insufficient resources to respond properly to all random access preambles received by the radio network node exists; and when it is determined that a condition indicative of the radio network node having insufficient resources to respond properly to all random access preambles received by the radio network node does exist, including, in a Medium Access Control, MAC, Protocol Data Unit, PDU, a request to extend the time period during which the unserved UE waits for reception of a MAC Random Access Response, RAR; and transmitting the MAC PDU including said request to the unserved UE. ### Claim 2 (depends on 1) The method according to claim 1, wherein the MAC PDU comprises a MAC header including a Backoff Indicator subheader and wherein the including of the request comprises including the request in one or more of the fields of the Backoff Indicator subheader. ### Claim 3 (depends on 2) The method according to claim 2, wherein the Backoff Indicator subheader comprises at least one Reserved field and wherein the including of the request comprises including the request in one or more of the at least one Reserved field of the Backoff Indicator subheader. ### Claim 4 (depends on 3) The method according to claim 3, wherein the Backoff Indicator subheader comprises at least one Reserved field and wherein the including of the request comprises including the request in only one of the at least one Reserved field of the Backoff Indicator subheader. ### Claim 5 (depends on 4) The method according to claim 4, wherein the Backoff Indicator subheader comprises two Reserved fields and wherein the including of the request comprises including the request in only one of the two Reserved fields of the Backoff Indicator subheader. ### Claim 6 (depends on 5) The method according to claim 5, wherein the including of the request comprises altering the setting of the Reserved field of the Backoff Indicator subheader to include a value representing said request. ### Claim 7 (depends on 1) The method claim 1, wherein receiving of the random access preamble comprises receiving the random access preamble on a Physical Random Access Channel, PRACH. ### Claim 8 (depends on 1) The method according to claim 1, further comprising: transmitting at least one MAC RAR to the unserved UE when previously insufficient resources becomes available. ### Claim 9 A method performed by a user equipment, UE, the method comprising: transmitting a random access preamble to a radio network node; receiving a MAC PDU from the radio network node, the MAC PDU comprising a request to extend the time period during which the UE waits for reception of a MAC Random Access Response, RAR, from the radio network node; and in response thereto starting a timer and monitoring a Physical Downlink Control Channel, PDCCH, for reception of the MAC RAR until the timer has reached a maximum time limit, the maximum time limit corresponding to the extended time period. ### Claim 10 (depends on 9) The method according to claim 9, wherein the MAC PDU comprises a MAC header including a Backoff Indicator subheader and wherein one or more fields of the Backoff Indicator subheader includes said request. ### Claim 11 (depends on 10) The method according to claim 10, wherein the Backoff Indicator subheader comprises at least one Reserved field and wherein one or more of the at least one Reserved field of the Backoff Indicator subheader includes said request. ### Claim 12 (depends on 11) The method according to claim 11, wherein the Backoff Indicator subheader comprises at least one Reserved field and wherein only one of the at least one Reserved field of the Backoff Indicator subheader includes said request. ### Claim 13 (depends on 12) The method according to claim 12, wherein the Backoff Indicator subheader comprises two Reserved fields and wherein only one of the Reserved fields of the Backoff Indicator subheader includes said request. ### Claim 14 (depends on 13) The method according to claim 13, wherein the Reserved field of the Backoff Indicator subheader is set to a value representing said request. ### Claim 15 (depends on 9) The method according to claim 9, wherein transmitting of the random access preamble comprises transmitting the random access preamble on a Physical Random Access Channel, PRACH. ### Claim 16 A radio network node comprising: a receiver configured to receive a random access preamble from an unserved user equipment, UE; a transmitter; a processor; and a memory storing computer program code, which, when run in the processor causes the radio network node (700) to: determine, upon receiving the random access preamble, whether a condition indicative of the radio network node having insufficient resources to respond properly to all random access preambles received by the radio network node exists; and when it is determined that a condition indicative of the radio network node having insufficient resources to respond properly to all random access preambles received by the radio network node does exist, including, in a Medium Access Control, MAC, Protocol Data Unit, PDU, a request to extend the time period during which the unserved UE waits for reception of a MAC Random Access Response, RAR; and transmit, via the transmitter, the MAC PDU including said request to the unserved UE. ### Claim 17 (depends on 16) The radio network node according to claim 16, wherein the MAC PDU comprises a MAC header including a Backoff Indicator subheader and wherein the memory and the computer program code are configured to, with the processor, cause the radio network node to include the request in one or more of the fields of the Backoff Indicator subheader. ### Claim 18 (depends on 17) The radio network node according to claim 17, wherein the Backoff Indicator subheader comprises at least one Reserved field and wherein the memory and the computer program code are configured to, with the processor, cause the radio network node to include the request in one or more of the at least one Reserved field of the Backoff Indicator subheader. ### Claim 19 (depends on 18) The radio network node according to claim 18, wherein the Backoff Indicator subheader comprises at least one Reserved field and wherein the memory and the computer program code are configured to, with the processor, cause the radio network node to include the request in only one of the at least one Reserved field of the Backoff Indicator subheader. ### Claim 20 (depends on 19) The radio network node according to claim 19, wherein the Backoff Indicator subheader comprises two Reserved fields and wherein the memory and the computer program code are configured to, with the processor, cause the radio network node to include the request in only one of the Reserved fields of the Backoff Indicator subheader. ### Claim 21 (depends on 20) The radio network node according to claim 20, wherein the memory and the computer program code are configured to, with the processor, cause the radio network node to alter the setting of the Reserved field of the Backoff Indicator subheader to include a value representing said request. ### Claim 22 (depends on 16) The radio network node according to claim 16, wherein the receiver is configured to receive the random access preamble from the unserved UE on a Physical Random Access Channel, PRACH. ### Claim 23 (depends on 16) The radio network node according to claim 16, wherein the transmitter is configured to transmit at least one MAC RAR to the unserved UE when previously insufficient resources becomes available. ### Claim 24 A user equipment, UE, comprising: a transmitter configured to transmit, to a radio network node, a random access preamble; a receiver configured to receive a MAC PDU from the radio network node, the MAC PDU comprising a MAC header including a request to extend the time period during which the UE waits for reception of a MAC Random Access Response, RAR from the radio network node; a processor; and a memory storing computer program code, which, when run in the processor causes the UE to, after reception of said request: start a timer and monitor a Physical Downlink Control Channel, PDCCH for reception, via the receiver of the MAC RAR until the timer has reached a maximum time limit, the maximum time limit corresponding to the extended time period. ### Claim 25 (depends on 24) The UE according to claim 24, wherein the MAC PDU comprises a MAC header including a Backoff Indicator subheader and wherein one or more fields of the Backoff Indicator subheader include said request. ### Claim 26 (depends on 25) The UE according to claim 25, wherein the Backoff Indicator subheader comprises at least one Reserved field and one or more of the Reserved fields of the Backoff Indicator subheader includes said request. ### Claim 27 (depends on 26) The UE according to claim 26, wherein the Backoff Indicator subheader comprises at least one Reserved field and wherein only one of the at least one Reserved field of the Backoff Indicator subheader includes said request. ### Claim 28 (depends on 27) The UE according to claim 27, wherein the Backoff Indicator subheader comprises two Reserved fields and wherein only one of the Reserved fields of the Backoff Indicator subheader includes said request. ### Claim 29 (depends on 28) The UE according to claim 28, wherein the Reserved field of the Backoff Indicator subheader is set to a value representing said request.