# Too many extra samples at the end of the transmitted packets **URL:** \ **Category:** GNU Radio\ **Created:** [November 10, 2014, 3:37pm UTC](https://www.ruby-forum.com/t/too-many-extra-samples-at-the-end-of-the-transmitted-packets/233003 "2014-11-10T15:37:21Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [November 10, 2014, 3:37pm UTC](https://www.ruby-forum.com/t/too-many-extra-samples-at-the-end-of-the-transmitted-packets/233003/1 "2014-11-10T15:37:21Z")
Hello, I am using narrowband benchmark\_tx.py example to transmit packets. Each single packet is separated from its neighbors by a second. The parameters I am using: benchmark\_tx\_modified.py -m gmsk -s 4000 -r 1000000 --tx-amplitude=1 -f 2.402G -A TX/RX --tx-gain=25 benchmark\_rx\_modified.py -m gmsk -r 1000000 -f 2.402G -A RX2 --rx-gain=0 At the receiver side (different USRP device), I am converting the complex stream into magnitude\_squared then into a file sink. What I should receive according to parameters above is a packet of 64000 samples or a bit more (for preamble and synch issues). This is because sps (sample per symbol) equals to 2. (4000 \* 8 \* 2 = 64000). However, when displaying the content of the file sink on a graph, I can obviously notice extra ~31500 samples!!! What could these extra ~31500 samples be? Please have a look at the attached image. I tried different packet sizes, modulations, etc, but there are still extra ~31500 samples. Thanks, Zaher ---
**Author:** ![mzaherm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/2bfe46/32.png) [@mzaherm](https://www.ruby-forum.com/u/mzaherm)\ **Post date:** [December 3, 2014, 11:36am UTC](https://www.ruby-forum.com/t/too-many-extra-samples-at-the-end-of-the-transmitted-packets/233003/2 "2014-12-03T11:36:15Z")
Hello, I have also noticed similar problem for my CSMA project. Fadzli,