# US 2023/0057059 A1 · Time-division multiplexing scheduler and scheduling device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0057059 A1 - Document ID: US20230057059A1 - Status: Published application - Kind: A1 - Application number: 17/974,915 - Filed: 2022-10-27 - Published: 2023-02-23 - Earliest claimed: 2020-12-18 - Assignees: Realtek Semiconductor Corp. - Applicants: Realtek Semiconductor Corporation - Inventors: KUO-CHENG LU; YU-MEI PAN; YUNG-CHANG LIN - Web page: https://patentgrep.com/patent/US20230057059A1 ## CPC - H04L 47/6275: based on priority - H04L 49/351: for local area network [LAN], e.g. Ethernet switches - H04L 49/501: {Overload detection} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A time-division multiplexing (TDM) scheduler determines a service order for serving N packet transmission requesters. The TDM scheduler includes: N current count value generators configured to serve the N packet transmission requesters respectively, and generate N current count values according to parameters of the N packet transmission requesters, a previous scheduling result generated by the EDD scheduler previously, and a predetermined counting rule; and an earliest due date (EDD) scheduler configured to generate a current scheduling result for determining the service order according to the N current count values and a predetermined urgency decision rule, wherein an extremum of the N current count values relates to one of the N packet transmission requesters, and the EDD scheduler selects this requester as the one to be served preferentially. ## Claims ### Claim 1 A time-division multiplexing (TDM) scheduler capable of determining service order for serving N packet transmission requesters, wherein the N is an integer greater than one, and the TDM scheduler comprises: N current count value generators configured to serve the N packet transmission requesters respectively, and generate N current count values according to parameters of the N packet transmission requesters, a previous scheduling result, and a predetermined counting rule; and an earliest due date (EDD) scheduler configured to generate a current scheduling result according to the N current count values and a predetermined urgency decision rule, wherein the current scheduling result determines the service order for serving the N packet transmission requesters, and the previous scheduling result is generated by the EDD scheduler prior to generation of the current scheduling result. ### Claim 2 (depends on 1) The TDM scheduler of claim 1, wherein the EDD scheduler includes: a conversion circuit configured to convert the N current count values into N priority values according to a predetermined conversion rule; and a decision circuit configured to generate the current scheduling result according to the N priority values. ### Claim 3 (depends on 2) The TDM scheduler of claim 2, wherein the decision circuit selects one of the N packet transmission requesters related to an extreme value of the N priority values as a top-priority target, and the top-priority target has a highest ranking of the service order. ### Claim 4 (depends on 2) The TDM scheduler of claim 2, wherein the conversion circuit refers to a demand status of each of the N packet transmission requesters according to the predetermined conversion rule and thereby generates the N priority values; the demand status is in one of a first state and a second state; the first state is indicative of at least one packet waiting to be transmitted; the second state is indicative of no packet waiting to be transmitted; and each of the N packet transmission requesters in the second state is excluded from being a top-priority target. ### Claim 5 (depends on 2) The TDM scheduler of claim 2, wherein the conversion circuit refers to a minimum service interval state value of each of the N packet transmission requesters according to the predetermined conversion rule and thereby generates the N priority values; the minimum service interval state value indicates whether a requester of the N packet transmission requesters in connection with the minimum service interval state value waits to be served for a period longer than a time threshold; and on condition that the requester waits to be served for the time threshold, the requester is eligible to be a top-priority target. ### Claim 6 (depends on 1) The TDM scheduler of claim 1, wherein an extreme value of the N current count values is related to one of the N packet transmission requesters; the extreme value is a minimum/maximum value of the N current count values; and the EDD scheduler selects the one of the N packet transmission requesters related to the extreme value as a top-priority target to be served. ### Claim 7 (depends on 6) The TDM scheduler of claim 6, wherein in a circumstance that each of X count values of the N current count values is equal to the extreme value and the X is an integer greater than one, the X count values are related to X requesters of the N packet transmission requesters, and the EDD scheduler selects one of the X requesters having a top service priority as the top-priority target according to predetermined priority rankings of the N packet transmission requesters. ### Claim 8 (depends on 1) The TDM scheduler of claim 1, wherein the EDD scheduler generates the current scheduling result further according to a demand status of each of at least a part of the N packet transmission requesters; the demand status is in one of a first state and a second state; the first state is indicative of at least one packet waiting to be transmitted; and the second state is indicative of no packet waiting to be transmitted. ### Claim 9 (depends on 8) The TDM scheduler of claim 8, wherein each of the N packet transmission requesters in the second state is excluded from being a top-priority target. ### Claim 10 A time-division multiplexing (TDM) scheduling device, comprising: a TDM scheduler including: N current count value generators configured to serve N packet transmission requester groups respectively, and generate N current count values according to parameters of the N packet transmission requester groups, a previous scheduling result, and a predetermined counting rule, wherein the N is an integer greater than one; and an earliest due date (EDD) scheduler configured to generate a current scheduling result according to the N current count values and a predetermined urgency decision rule, wherein the previous scheduling result is generated by the EDD scheduler prior to generation of the current scheduling result; and a transmission port scheduler including: N scheduling circuits configured to serve the N packet transmission requester groups respectively, wherein each of the N packet transmission requester groups includes one or more transmission ports, a first group of the N packet transmission requester groups is served by one of the N scheduling circuits which selects a target transmission port of the one or more transmission ports of the first group, the first group is any of the N packet transmission requester groups, and the N scheduling circuits select N target transmission ports in total; and a multiplexer configured to output a transmission port selection signal according to the current scheduling result indicative of a top-priority group of the N packet transmission requester groups, wherein the transmission port selection signal indicates that one of the N target transmission ports is selected as a select transmission port for the top-priority group, the select transmission port is one of M transmission port(s) of the top-priority group and allowed to transmit, and the M is a positive integer. ### Claim 11 A time-division multiplexing (TDM) scheduling device for serving N packet transmission requester groups, comprising: a TDM scheduler configured to select one of the N packet transmission requester groups as a select packet transmission requester group, wherein the select packet transmission requester group includes M transmission ports and the M is a positive integer greater than one; and a transmission port scheduler configured to select one of the M transmission ports as a select transmission port according to scheduling parameters and a predetermined algorithm. ### Claim 12 (depends on 11) The TDM scheduling device of claim 11, wherein the transmission port scheduler includes: N scheduling circuits serving the N packet transmission request groups respectively and thereby generating N transmission port selection signals respectively; and a multiplexer outputting one of the N transmission port selection signals as a select port signal according to a requester group selection signal, wherein the select port signal indicates the select transmission port and the requester group selection signal is included in a current scheduling result from the TDM scheduler. ### Claim 13 (depends on 11) The TDM scheduling device of claim 11, wherein the scheduling parameters includes: a demand status of each of the M transmission ports; a weighting of each of the M transmission ports; a mode parameter indicating that the select packet transmission request group is in a line rate mode or an oversubscription mode. ### Claim 14 (depends on 13) The TDM scheduling device of claim 13, wherein the mode parameter is provided by the TDM scheduler. ### Claim 15 (depends on 11) The TDM scheduling device of claim 11, wherein the predetermined algorithm is a weighted round robin (WRR) algorithm.