Synchronizing Uplink and Downlink Transmissions in a Wireless Device

[0012]Thus, by buffering uplink data until a downlink grant is received if a wireless device is in a reduced-power state (or possibly even if the wireless device is in an active state, if no downlink transmissions are being performed) instead of immediately transitioning to an active state to transmit the uplink data, the wireless device may be prevented from re-entering the active state for a period of time (e.g., until a downlink grant is received) and/or may more quickly transition from an active state to a reduced-power state, which may advantageously reduce battery consumption of the wireless device for the time period between generating/buffering the uplink data and receiving the downlink grant. Particularly when used in conjunction with suitable applications and combined with use of an uplink transmission timer or other fail-safe technique to avoid ill conditions which could result from buffering uplink data in some circumstances, the method for synchronizing uplink and downlink transmissions presented herein may thus provide an excellent means of reducing battery consumption of a wireless device without significantly sacrificing data throughput or quality of user experience.

While this may conserve power under some circumstances, the amount of power savings are highly dependent on traffic patterns, and it is possible that no savings will be realized at all if not enough continuous inactivity is observed.

In particular, certain types of traffic patterns, such as bi-directional interactive and multimedia traffic, can negatively impact the length of periods of inactivity between traffic bursts, particularly if uplink and downlink bursts are offset from each other, which may reduce power savings or prevent a wireless device from entering a reduced-power state between bursts at all.

Furthermore, if a wireless device is forced, due to non-synchronous traffic patterns, into operating in a continuous active state, this may not only impact the battery life of the wireless device, but may also cause device temperature to escalate quickly.

These problems are further aggravated in areas with low signal strength, such as cell edges, where high transmission power may be required.