Subject: [T2TRG] Fw: Some practical deployment experience of data aggregation in IOT/LP_WAN

From: "[email-masked]" <[email-masked]>
Date: Thu, 28 Apr 2016 16:56:46 +0800

Hi，folks

I am glad to introduce my existing deployment experience as mentioned yesterday.
Since 2012, I have been deploying intelligent agricultural systems for some farms. At beginning, I used CROSSBOW's sensors and nodes, now,I also use other companys' products. 
In each greenhouse there are many sensors such as temperature, humidity, and one Cluster Header(gateway). One or more sensors were integrated into one wireless node which were controlled by TinyOS. Sensor-generate-data is first transmitted to the Cluster Header by wireless node via 802.15.4 protocol and private mesh protocol. The Cluster Header forward these sensor-generate-data to a gateway through USB port(pl2303 or FTDI). The gateway will store these data temporarily and then encapsulate them into an aggregation chain and at the last send the aggregation chain to actual destination through WCDMA.
By doing this, it simplify implementation as well as to lower the cost because some greenhouses can not connect to internet through wired line. It would be a waste of bandwidth if initiated the transmission for every sensor's frame. Because each sensor-generate-data is very small: TinyOS header(5 bytes), Xmesh Header(0/7 bytes), Address information and Sequence number(8 bytes), payload(8 bytes). Therefore accounts very small proportion of the whole WCDMA packet. 
Actually, that does make sense in some LW-PAN scenarios: many sensors but each sensor has limit number of frames per day.

Regards
Xiaowei Qin