# US 2022/0286338 A1 · Packet format for transmission of data packets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0286338 A1 - Document ID: US20220286338A1 - Status: Published application - Kind: A1 - Application number: 17/641,301 - Filed: 2020-09-16 - Published: 2022-09-08 - Earliest claimed: 2019-09-17 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Miguel LOPEZ; Sebastian MAX; Leif WILHELMSSON; Dennis SUNDMAN - Web page: https://patentgrep.com/patent/US20220286338A1 ## CPC - H04L 27/2613: {Structure of the reference signals} - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 27/2666: {Acquisition of further OFDM parameters, e.g. bandwidth, subcarrier spacing, or guard interval length} - H04W 72/044: based on the type of the allocated resource - 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 packet format is disclosed for transmission of data packets over a communication channel, wherein transmission of one of the data packets utilizes a frequency bandwidth, and wherein the frequency bandwidth is dynamically variable between data packets. The packet format defines a frequency bandwidth detection field, wherein the frequency bandwidth detection field of a data packet has a first field content or a second field content, and wherein corresponding parts of the first and second field contents are orthogonal to each other. The first field content is indicative of that transmission of the data packet utilizes a first frequency bandwidth and the second field content is indicative of that transmission of the data packet utilizes a frequency bandwidth which is larger than the first frequency bandwidth. Corresponding methods and apparatuses for transmission/reception of data packets are also disclosed. ## Claims ### Claim 1 A packet format for transmission of data packets over a communication channel, transmission of one of the data packets utilizing a frequency bandwidth, the frequency bandwidth being dynamically variable between data packets, the packet format comprising: a frequency bandwidth detection field, the frequency bandwidth detection field of a data packet having one of a first field content and a second field content, and corresponding parts of the one of the first and second field contents are orthogonal to each other; and the first field content being indicative of that transmission of the data packet utilizes a first frequency bandwidth and the second field content being indicative of that transmission of the data packet utilizes a frequency bandwidth which is larger than the first frequency bandwidth. ### Claim 2 (depends on 1) The packet format of claim 1, wherein the first field content comprises at least one instance of a first orthogonal frequency division multiplex, OFDM, symbol, and the second field content comprises at least one instance of a second OFDM symbol, wherein the second OFDM symbol is a time reversed version of the first OFDM symbol. ### Claim 3 (depends on 2) The packet format of claim 2, wherein the first field content consists of two instances of the first OFDM symbol and a first cyclic prefix, CP, wherein the first CP is a copy of a portion of the first OFDM symbol, and the second field content consists of two instances of the second OFDM symbol and a second CP, wherein the second CP is a copy of a portion of the second OFDM symbol. ### Claim 4 (depends on 2) The packet format of claim 2, wherein corresponding parts are defined as instances of the first and second OFDM symbols. ### Claim 5 (depends on 1) The packet format of claim 1, wherein the frequency bandwidth is dynamically variable between at least two predetermined frequency bandwidths: the first frequency bandwidth and one or more second frequency bandwidths. ### Claim 6 (depends on 1) The packet format of claim 1, further defining one or more of: a synchronization field comprising a repetitive time domain pattern; a control field utilizing the first frequency bandwidth when the frequency bandwidth detection field has the first field content and utilizing a second frequency bandwidth when the frequency bandwidth detection field has the second field content; and a data field suitable for transmission over the frequency bandwidth indicated by the frequency bandwidth detection field. ### Claim 7 (depends on 5) The packet format of claim 5, wherein the control field is indicative of which of the one or more second frequency bandwidths is utilized for transmission of the data packet. ### Claim 8 (depends on 6) The packet format of claim 6, wherein at least one of: the synchronization field is a legacy short training field, L-STF; and the control field is a signaling field, SIG. ### Claim 9 (depends on 1) The packet format of claim 1, wherein at least one of: the data packet is a physical layer convergence protocol data unit, PPDU; and the frequency bandwidth detection field is a legacy long training field, L-LTF. ### Claim 10 (depends on 1) The packet format of claim 1, wherein the packet format is for use in compliance with at least one of IEEE802.11ax and IEEE802.11be. ### Claim 11 (depends on 1) The packet format of claim 1, wherein the second field content is a time reversed version of the first field content. ### Claim 12 (depends on 1) The packet format of claim 1, wherein the second field content consists of two or more parts, wherein at least one part is a time reversed version of the corresponding part of the first field content. ### Claim 13 (depends on 1) The packet format of claim 1, wherein the first field is a long training field, L-LTF. ### Claim 14 A method for transmission of data packets over a communication channel, the data packets having a packet format, transmission of one of the data packets utilizing a frequency bandwidth, the frequency bandwidth being dynamically variable between data packets, the method comprising: populating a frequency bandwidth detection field of the packet format with one of a first field content and a second field content, corresponding parts of the first and second field contents being orthogonal to each other, and the first field content being selected when transmission of the data packet utilizes a first frequency bandwidth and the second field content being selected when transmission of the data packet utilizes a frequency bandwidth which is larger than the first frequency bandwidth. ### Claim 15 (depends on 14) The method of claim 14, wherein the first field content comprises at least one instance of a first orthogonal frequency division multiplex, OFDM, symbol, and the second field content comprises at least one instance of a second OFDM symbol, wherein the second OFDM symbol is a time reversed version of the first OFDM symbol. ### Claim 16 A method for reception of data packets over a communication channel, the data packets having a packet format, transmission of one of the data packets utilizing a frequency bandwidth, the frequency bandwidth being dynamically variable between data packets, the method comprising: detecting whether a frequency bandwidth detection field of the packet format has a first field content or a second field content, corresponding parts of the first and second field contents being orthogonal to each other; processing the data packet as received over a first frequency bandwidth when the first field content is detected; and processing the data packet as received over frequency bandwidth which is larger than the first frequency bandwidth when the second field content is detected. ### Claim 17 (depends on 14) The method of claim 14, wherein the first field content comprises at least one instance of a first orthogonal frequency division multiplex, OFDM, symbol, and the second field content comprises at least one instance of a second OFDM symbol, wherein the second OFDM symbol is a time reversed version of the first OFDM symbol. ### Claim 18 (canceled) ### Claim 19 An apparatus for transmission of data packets over a communication channel, the data packets having a packet format, transmission of one of the data packets utilizing a frequency bandwidth, the frequency bandwidth being dynamically variable between data packets, the apparatus comprising controlling circuitry configured to cause: population of a frequency bandwidth detection field of the packet format with one of a first field content and a second field content, corresponding parts of the first and second field contents are orthogonal to each other, and the first field content being for indicating transmission of the data packet utilizing a first frequency bandwidth and the second field content being for indicating transmission of the data packet utilizing a frequency bandwidth which is larger than the first frequency bandwidth. ### Claim 20 An apparatus for reception of data packets over a communication channel, wherein the data packets have a packet format, transmission of one of the data packets utilizing a frequency bandwidth, the frequency bandwidth being dynamically variable between data packets, the apparatus comprising controlling circuitry configured to cause: detection of whether a frequency bandwidth detection field of the packet format has a first field content or a second field content, corresponding parts of the first and second field contents being orthogonal to each other; processing of the data packet as received over a first frequency bandwidth when the first field content is detected; and processing of the data packet as received over frequency bandwidth which is larger than the first frequency bandwidth when the second field content is detected. ### Claim 21 (depends on 19) The apparatus of claim 19, wherein the first field content comprises at least one instance of a first orthogonal frequency division multiplex, OFDM, symbol, and the second field content comprises at least one instance of a second OFDM symbol, wherein the second OFDM symbol is a time reversed version of the first OFDM symbol. ### Claim 22 (depends on 19) The apparatus of claim 19, wherein the apparatus is comprised in a transmitter. ### Claim 23 (depends on 22) The transmitter of claim 22, wherein the first field content comprises at least one instance of a first orthogonal frequency division multiplex, OFDM, symbol, and the second field content comprises at least one instance of a second OFDM symbol, wherein the second OFDM symbol is a time reversed version of the first OFDM symbol. ### Claim 24 (depends on 20) The apparatus of claim 20, wherein the apparatus is comprised in a receiver. ### Claim 25 (depends on 24) The receiver of claim 24, wherein the first field content comprises at least one instance of a first orthogonal frequency division multiplex, OFDM, symbol, and the second field content comprises at least one instance of a second OFDM symbol, wherein the second OFDM symbol is a time reversed version of the first OFDM symbol. ### Claim 26 (canceled) ### Claim 27 (canceled)