4

我试图了解 LTE 和 UMTS/HSPA+ 如何从全功率状态过渡，以及当移动设备的无线电以全功率运行时，塔上占用了哪些资源。

我看过Ch。High Performance Browser Networking的 7 和 8 以及书中提到的 AT&T Research 文章中，但他们没有直接解决这个问题。

  • UMTS（DCH 到 FACH）中从全功率到半功率转换的超时时间几乎总是 5 秒，还是 5 秒值（在上面的 AT&T 研究链接中提到）来自哪里？

  • 当在超时到期之前发送次要流量时，从全功率 DCH 状态转换的 UMTS 超时是否重置，或者它是否取决于随后通过共享低电平处理此类次要流量是否足够？ - 低带宽半功率 FACH 状态下的高速通道？

  • 从全功率状态过渡到 LTE 的超时时间是多少？

  • 在 UMTS 和 LTE 全功率状态下，塔会占用哪些资源，对运营商有何影响？

  • 从全功率状态的转变在多大程度上是由移动设备的电池消耗问题决定的，而不是运营商对塔的实际资源节约？例如，如果设备连接到充电器，是否允许或有意义始终使用 UMTS 和 LTE 在全功率状态下操作移动设备的无线电？

4

3 回答 3

1

奇怪的是，从 DCH 到 FACH 的 RRC 状态需要 5 秒，通常比这更快。它挂起的时间越长，网络与您的 RRC 实例关联的 RRC 资源就越多，使 RRC 状态挂起时间尽可能短，因为它节省计算和频谱资源，这符合良好设计的最佳利益。

因此，回到您的主要问题，RRC STATE (CELL DCH) 消耗的功率最多，RRC STATE (CELL FACH) 消耗功率突发，RRC STATE (IDLE) 消耗最少。突发来自小区重选状态和 RRC 连接建立请求。

这是一个正确的 rrc 状态图（http://images.books24x7.com/bookimages/id_6399/fig209_01.jpg）

这是我在谷歌图片上找到的 rrc 状态功耗图（http://3.bp.blogspot.com/-NoMR5oNLbCs/T3H1i0bsdgI/AAAAAAAAAW0/pv0G-tG0auk/s1600/Power+Consumption+Vs+RRC+states.png )

现在，如果文章的数据是正确的，我可以推断出测量结果表明 Ue 中的 RRC 状态机处于“滞后”状态，Ue 需要 5 秒才能决定下一个 RRC 状态。那么它可能是网络设计和降级问题。

于 2014-07-03T19:20:03.570 回答
0

UMTS:

The delay from transitioning to DCH to FACH is governed by a timer called T1, and in this case the network has configured it to be 5 seconds. Whatever the value is, it is a compromise between device battery consumption and managing the signalling load between the network elements.

For mobile applications that exchange small packets periodically but infrequently a long timer causes the device to remain in high power state for many additional and unnecessary seconds, draining battery.

Prior to 3GPP Release 8 this issue was addressed by device manufacturers so that instead of waiting for the network initiated transition to FACH, the device would send a signalling connection release indication (SCRI) after it was done sending and receiving data. This would place the device in idle mode, the lowest power consumption state.

However, this solution had an downfall: the SCRI would cause unnecessary signalling load between the network elements when the RAB was being released and set up again frequently.

This was addressed in Release 8 so that a specific cause value (UE requested PS data session end) in SCRI explicitly states to the network that the device is done sending and receiving data. This allows the network to distinguish between different reasons for releasing the connection, and if it is happening too frequently, it could deny the request to release the connection and avoid signalling load.

See Fast Dormancy Best Practices by GSMA for more info.

LTE:

LTE is simpler as there are only two RRC states, connected and idle. The timers are still controlled by the network, but remaining in RRC connected state in LTE is not as harmful to the UE as discontinuous reception (DRX) helps to keep the power consumption lower. Also, transitioning between the two states does not cause as much signalling load in LTE, as it was a goal of the design.

于 2015-04-10T12:23:47.673 回答
0

RRC-DCH 状态总是具有最高功率状态。RRC-FACH 状态低于 DCH 状态。然后是 RRC-URA 状态，这是它们中最少的。

快速休眠有助于将 Ue 从最高功耗状态切换到最低功耗状态。在连接模式下的功率级别 DCH>FACH>URA。

于 2018-06-15T07:55:22.780 回答