Trigger frames adapted to packet-based policies in an 802.11 network
摘要
說明書
To be precise, the Trigger Frame mechanism provides only generic RU in which padding must be performed to ensure reaching the end of the TXOP and to avoid interference with legacy nodes. Such padding adds to the overall cost of overhead. This additional overhead cost due to padding is exacerbated for the so-called small packets, since they use a very little portion of allocated RUs.
So, particularly for small packets, the gain in reducing the waiting time may not be enough to compensate the loss due to padding. As a result, the total overhead may not be reduced, contrary to the intended goal when introducing the Trigger Frame mechanism.
Apart from the small packet situation, different kinds of data traffic usually cohabit in the various RUs, each with different requirements in term of data quantity to transmit, latency. TxOP duration, etc. Such heterogeneity of the different PPDUs transmitted by the nodes may result in having a huge quantity of padding data in some RUs, and hence in drastically reducing the efficiency of the channel usage.
It may be noted that the padding issue may also be accentuated by the use of different modulations (Modulation and Coding Scheme) to handle the distance (node to AP) and Signal Noise Ratio variation (channel conditions change) through the different paths, i.e. through the different RUs involving different nodes.
Thus, there is a need to improve this situation and to reduce the impact of padding in network usage efficiency.
In addition, it may also be taken advantage of the different kinds of data traffic cohabiting in the various RUs to improve the usage of the network.
