A method of wireless communication, comprising: receiving, at a wireless device (120a-i; 120m; 302), a trigger message from an access point allocating a first subset of wireless transmission resources of a plurality of wireless transmission resources; the wireless device (120a-i; 120m; 302) is from a plurality of stations (120a-i; 120m; 302) in wireless communication with the access point over the plurality of wireless transmission resources; the trigger message allocates the first subset of wireless transmission resources to a first group of stations (120a-i; 120m; 302) from the plurality of stations (120a-i; 120m; 302), wherein accessing the first subset of wireless transmission resources by the first group of stations (120a-i; 120m; 302) is contention based and the trigger message comprises a collision resolution mechanism related to a data or frame type; and the trigger message allocates each wireless transmission resource from a second subset of wireless transmission resources of the plurality of wireless transmission resources to only one station (120a-i; 120m; 302) of the plurality of stations (120a-i; 120m; 302) without contention; determining whether to transmit over the first subset of wireless transmission resources based on the collision resolution mechanism; and selectively transmitting one or more transmissions over the first subset of wireless transmission resources based on the collision resolution mechanism, wherein: the one or more transmissions from the wireless device over the first subset of wireless transmission resources are time synchronized and frequency synchronized among transmissions by the plurality of stations (120a-i; 120m; 302) over the first subset and the second subset of wireless transmission resources; and the collision resolution mechanism limits the number of stations (120a-i; 120m; 302) contending for a resource by excluding one or more of the plurality of stations (120a-i; 120m; 302) from the trigger message allocations such that the probability that only one station (120a-i; 120m; 302) transmits is above a threshold. receiving, at a wireless device (120a-i; 120m; 302), a trigger message from an access point allocating a first subset of wireless transmission resources of a plurality of wireless transmission resources; the wireless device (120a-i; 120m; 302) is from a plurality of stations (120a-i; 120m; 302) in wireless communication with the access point over the plurality of wireless transmission resources; the trigger message allocates the first subset of wireless transmission resources to a first group of stations (120a-i; 120m; 302) from the plurality of stations (120a-i; 120m; 302), wherein accessing the first subset of wireless transmission resources by the first group of stations (120a-i; 120m; 302) is contention based and the trigger message comprises a collision resolution mechanism related to a data or frame type; and the trigger message allocates each wireless transmission resource from a second subset of wireless transmission resources of the plurality of wireless transmission resources to only one station (120a-i; 120m; 302) of the plurality of stations (120a-i; 120m; 302) without contention; determining whether to transmit over the first subset of wireless transmission resources based on the collision resolution mechanism; and selectively transmitting one or more transmissions over the first subset of wireless transmission resources based on the collision resolution mechanism, wherein: the one or more transmissions from the wireless device over the first subset of wireless transmission resources are time synchronized and frequency synchronized among transmissions by the plurality of stations (120a-i; 120m; 302) over the first subset and the second subset of wireless transmission resources; and the collision resolution mechanism limits the number of stations (120a-i; 120m; 302) contending for a resource by excluding one or more of the plurality of stations (120a-i; 120m; 302) from the trigger message allocations such that the probability that only one station (120a-i; 120m; 302) transmits is above a threshold. the one or more transmissions from the wireless device over the first subset of wireless transmission resources are time synchronized and frequency synchronized among transmissions by the plurality of stations (120a-i; 120m; 302) over the first subset and the second subset of wireless transmission resources; and the collision resolution mechanism limits the number of stations (120a-i; 120m; 302) contending for a resource by excluding one or more of the plurality of stations (120a-i; 120m; 302) from the trigger message allocations such that the probability that only one station (120a-i; 120m; 302) transmits is above a threshold.