A method of operating a first wireless terminal to communicate with a second wireless terminal in a network wherein individual traffic transmission slots are associated with multiple request blocks (302, 306), different request blocks corresponding to a traffic transmission slot having different request block priorities, the method comprising: determining a first transmission priority for a first traffic transmission slot, the traffic transmission slots being part of a timing structure; and when said determined transmission priority is the highest request block priority, transmitting a first transmission request corresponding to a first traffic transmission slot using a transmission request block having said determined first transmission priority; determining a second transmission priority for a second traffic transmission slot, at a point in time subsequent to determining said first transmission priority, wherein determining said second transmission priority being performed as a function of: quality of service requirements of traffic data waiting to be transmitted by said first wireless terminal to said second wireless terminal and historical information based on at least one of: i) requests made in highest priority transmission request blocks and ii) responses detected in highest priority request response blocks. wherein when said first determined transmission priority is the highest, the method further including: making a decision whether or not to cancel the requested transmission, based on at least one signal received from another device, said signal being transmitted in one of a highest priority transmission request block or a highest priority transmission request response block corresponding to said first traffic transmission slot; wherein the first wireless terminal has a dedicated transmission unit within the highest priority transmission request response block, different transmission units (316, 318) within the highest priority request response block having different transmission unit priorities; and wherein making said decision is performed as a function of said different transmission unit priorities when said signal is a signal received in the highest priority request response block. determining a first transmission priority for a first traffic transmission slot, the traffic transmission slots being part of a timing structure; and when said determined transmission priority is the highest request block priority, transmitting a first transmission request corresponding to a first traffic transmission slot using a transmission request block having said determined first transmission priority; determining a second transmission priority for a second traffic transmission slot, at a point in time subsequent to determining said first transmission priority, wherein determining said second transmission priority being performed as a function of: quality of service requirements of traffic data waiting to be transmitted by said first wireless terminal to said second wireless terminal and historical information based on at least one of: i) requests made in highest priority transmission request blocks and ii) responses detected in highest priority request response blocks. wherein when said first determined transmission priority is the highest, the method further including: making a decision whether or not to cancel the requested transmission, based on at least one signal received from another device, said signal being transmitted in one of a highest priority transmission request block or a highest priority transmission request response block corresponding to said first traffic transmission slot; wherein the first wireless terminal has a dedicated transmission unit within the highest priority transmission request response block, different transmission units (316, 318) within the highest priority request response block having different transmission unit priorities; and wherein making said decision is performed as a function of said different transmission unit priorities when said signal is a signal received in the highest priority request response block. quality of service requirements of traffic data waiting to be transmitted by said first wireless terminal to said second wireless terminal and historical information based on at least one of: i) requests made in highest priority transmission request blocks and ii) responses detected in highest priority request response blocks. making a decision whether or not to cancel the requested transmission, based on at least one signal received from another device, said signal being transmitted in one of a highest priority transmission request block or a highest priority transmission request response block corresponding to said first traffic transmission slot;