ifference between DCF and EDCA. In DCF, all the stations use the same values and therefore have the same priority for transmitting on the channel. In the case of EDCA, each of the different access priorities uses a different range of waiting intervals and back- off counters; therefore, stations with higher-access priority are assigned shorter intervals. The standard also includes a packet-bursting mode that allows a WAP or a mobile station to reserve a channel and send three to five packets in sequence. EDCA can ensure that voice transmissions wait less than data transmissions, but it lacks a mechanism to deliver truly consistent delay. Polled Access Delivering true consistent delay is the role of the optional oper- ating mode Polled Access. Polled Access periodically broadcasts a control message that forces all stations to treat the channel as busy and not attempt to transmit. During that period, the WAP polls each station that is defined for time-sensitive service. The Polled Access function requires that devices request a traffic profile regarding bandwidth, latency, and jitter. If the WAP lacks resources to meet the traffic profile, the WAP returns a busy signal. Polled Access is optional because WAPs that do not support the feature must be able to return a "service not avail- able" response to stations' profile requests. VoWLAN Support Solutions Although 802.11e will provide a more predictable WLAN environment, voice can still be carried over WLANs with the existing tools and techniques. In addition, the IEEE is beginning work on higher-capacity channels. It is developing the 802.11n radio link, with the goal of delivering throughput of 100Mbps. By employing MIMO, 802.11n will offer up to eight times the coverage and up to six times the speed of current 802.11g networks. In January 2006, the task group working on WLANs this faster standard for Wi-Fi settled on a draft proposal that was to be refined into a final specification. A few wireless networking manufacturers have released "pre-N" hardware in anticipa