# US 2014/0192724 A1 · Method, apparatus, and computer program product for contention access in wireless communication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192724 A1 - Document ID: US20140192724A1 - Status: Published application - Kind: A1 - Application number: 13/735,423 - Filed: 2013-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: Nokia Corporation - Applicants: Nokia Corporation - Inventors: Markku TURUNEN; Mika KASSLIN; Enrico RANTALA; Kari J. LEPPÄNEN; Sami VIRTANEN - Web page: https://patentgrep.com/patent/US20140192724A1 ## CPC - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Method, apparatus, and computer program product example embodiments enable contention for access to a wireless communications medium. In example embodiments, a method comprises initiating a channel access procedure by an apparatus; performing, by the apparatus, in response to the channel access procedure initiation, a random draw for permission to start contention with other member apparatuses of a group in which the apparatus belongs, the random draw being based on how many member apparatuses of the group are expected to compete for the wireless communications medium; and starting, by the apparatus, contention for access to the wireless communications medium, if the apparatus wins the random draw. ## Claims ### Claim 1 A method, comprising: initiating a channel access procedure by an apparatus; performing, by the apparatus, in response to the channel access procedure initiation, a random draw for permission to start contention with other member apparatuses of a group in which the apparatus belongs, the random draw being based on how many member apparatuses of the group are expected to compete for the wireless communications medium; and starting, by the apparatus, contention for access to the wireless communications medium, if the apparatus wins the random draw. ### Claim 2 (depends on 1) The method of claim 1, further comprising: waiting, by the apparatus, until another member apparatus of the group completes its access to the wireless communications medium if the apparatus did not win the random draw; performing, by the apparatus, a second random draw for permission to start a second contention with other members of the group, for access to the wireless communications medium, the second random draw being based on how many members of the group are expected to compete in the second random draw for permission to start contention for the wireless communications medium; and starting, by the apparatus, the second contention for access to the wireless communications medium, if the apparatus wins the second random draw. ### Claim 3 (depends on 1) The method of claim 1, wherein the channel access procedure initiation is triggered in response to receiving, by the apparatus, a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 4 (depends on 1) The method of claim 1, wherein the channel access procedure initiation is triggered in response to transmitting, by the apparatus, a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 5 (depends on 1) The method of claim 1, wherein the channel access procedure initiation is triggered in response to determining by the apparatus that a predetermined amount of time has elapsed from targeted transmission time of a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 6 (depends on 1) The method of claim 1, wherein the contention for access to the wireless communications medium is by carrier sense multiple access. ### Claim 7 An apparatus, comprising: at least one processor; at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: initiate a channel access procedure; perform in response to the channel access procedure initiation, a random draw for permission to start contention with other member apparatuses of a group in which the apparatus belongs, the random draw being based on how many member apparatuses of the group are expected to compete for the wireless communications medium; and start contention for access to the wireless communications medium, if the apparatus wins the random draw. ### Claim 8 (depends on 7) The apparatus of claim 7, further comprising: the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: wait until another member apparatus of the group completes its access to the wireless communications medium if the apparatus did not win the random draw; perform a second random draw for permission to start a second contention with other members of the group, for access to the wireless communications medium, the second random draw being based on how many members of the group are expected to compete in the second random draw for permission to start contention for the wireless communications medium; and start the second contention for access to the wireless communications medium, if the apparatus wins the second random draw. ### Claim 9 (depends on 7) The apparatus of claim 7, wherein the channel access procedure initiation is triggered in response to receiving, by the apparatus, a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 10 (depends on 7) The apparatus of claim 7, wherein the channel access procedure initiation is triggered in response to transmitting, by the apparatus, a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 11 (depends on 7) The apparatus of claim 7, wherein the channel access procedure initiation is triggered in response to determining by the apparatus that a predetermined amount of time has elapsed from targeted transmission time of a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 12 (depends on 7) The apparatus of claim 7, wherein the contention for access to the wireless communications medium is by carrier sense multiple access. ### Claim 13 A computer program product comprising computer executable program code recorded on a computer readable non-transitory storage medium, the computer executable program code comprising: code for initiating a channel access procedure by an apparatus; code for performing, by the apparatus, in response to the channel access procedure initiation, a random draw for permission to start contention with other member apparatuses of a group in which the apparatus belongs, the random draw being based on how many member apparatuses of the group are expected to compete for the wireless communications medium; and code for starting, by the apparatus, contention for access to the wireless communications medium, if the apparatus wins the random draw. ### Claim 14 (depends on 13) The computer program product of claim 13, further comprising: code for waiting, by the apparatus, until another member apparatus of the group completes its access to the wireless communications medium if the apparatus did not win the random draw; code for performing, by the apparatus, a second random draw for permission to start a second contention with other members of the group, for access to the wireless communications medium, the second random draw being based on how many members of the group are expected to compete in the second random draw for permission to start contention for the wireless communications medium; and code for starting, by the apparatus, the second contention for access to the wireless communications medium, if the apparatus wins the second random draw. ### Claim 15 (depends on 13) The computer program product of claim 13, wherein the channel access procedure initiation is triggered in response to receiving, by the apparatus, a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 16 (depends on 13) The computer program product of claim 13, wherein the channel access procedure initiation is triggered in response to transmitting, by the apparatus, a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 17 (depends on 13) The computer program product of claim 13, wherein the channel access procedure initiation is triggered in response to determining by the apparatus that a predetermined amount of time has elapsed from targeted transmission time of a wireless message including timing synchronization of the group of which the apparatus is a member. ### Claim 18 (depends on 13) The computer program product of claim 13, wherein the contention for access to the wireless communications medium is by carrier sense multiple access.