diff --git a/xep-0286.xml b/xep-0286.xml
index c2fcb34c..c8898a72 100644
--- a/xep-0286.xml
+++ b/xep-0286.xml
@@ -2,11 +2,13 @@
%ents;
+LTE Smartphone measurements <http://networks.nokia.com/system/files/document/lte_measurements_final.pdf>">
+A Close Examination of Performance and Power Characteristics of 4G LTE Networks <doi:2307636.2307658>">
]>
+
+
While the CPU cost of compression may directly translate to higher power @@ -122,13 +135,10 @@ power per bit than 3G networks as will be seen later in this document. However, CPU usage is also not guaranteed to rise due to compression. In the aforementioned deployment of stream compression, a - decrease in CPU utilization by a factor of 0.60 was observed due - to the fact that there were fewer packets that needed to be handled by the - OS (which also takes CPU time), and, potentially more importantly, less - data that needed to be TLS-encrypted (which is a much more CPU-expensive - operation than compression). + decrease in CPU utilization by a factor of 0.60 was observed, + presumably due to reductions in TLS and packet handling overhead. Therefore CPU time spent on compression (for ZLIB, at least; other - algorithms were not tested) should be considered negligable. + algorithms were not tested) can be considered negligable.
Supporting compression and performming a full flush on stanza boundaries
@@ -140,12 +150,10 @@
While the wide spread adoption of LTE has dramatically increased available
bandwidth on mobile devices, it has also increased power consumption.
According to one study, early LTE devices consumed 5–20% more power
- than their 3G counterparts
-
XMPP server and client implementers, bearing this increased power usage in
@@ -153,12 +161,11 @@
traffic to minimize network usage.
For the downlink, LTE user equipment
(UE) utilizes Orthogonal Frequency Division Multiplexing (OFDM), which is
- somewhat inefficient
-
If one is on 3G, transmitting a small amount of data will cause the radio to enter FACH mode which is significantly cheaper than its high power mode. On LTE radios, however, transmitting small amounts of data is vastly - more expensive per bit due to the higher tail-times (the time it takes - for the radio to change state). + more expensive per bit due to the higher tail-time (the time it takes + for the radio to change state) of approximately 11 seconds&huang12;. On LTE radios, one should transmit as much data from the client as possible when the radio is already on (eg. by placing messages in a send queue and executing the queue as a batch when the radio is on). @@ -199,10 +206,8 @@
These rules also apply to server operators: If the server receives data, - the phones radio is already on therefore you should send any pending - data. - Batching data to be sent and sending it all at once will help reduce - power consumption. + the phones radio is already on, therefore you should flush any pending + data as soon as possible after receiving data from a client.
&xep0138; provides stream level compression.
-&xep0322; allows XMPP streams to use the EXI XML format.
&xep0115; provides a mechanism for caching, and hence eliding, the disco#info requests needed to negotiate optional features. @@ -247,8 +251,8 @@
This XEP was originally written by Dave Cridland, and parts of his original work were used in this rewrite. - Thanks to Atlassian for allowing me to release hard numbers from their - XMPP compression deployment. + Thanks to Atlassian (HipChat) for allowing me to release numbers from + their XMPP compression deployment.