[USRP-users] Gen2 reader

mahran nedal mahran2010sawya at hotmail.com
Thu Dec 4 12:39:11 EST 2014


Thank you for reply Marcus . yes between transmissions the carrier wave dropped or in every cycle . My implementation based on EPC Class-1 Generation-2 protocol please see http://www.gs1.org/gsmp/kc/epcglobal/uhfc1g2  V2.2 (page 26,42). The reader or interrogator send the signal which contains a Query ,all the  communication parameters  includes inside the query  like preamble ,etc. the signal encoding by pulse interval encoding and modulated by ASK ,the tag receive the signal and back-scattering again to the reader ,through this time the carrier wave energize the tag for response . I success to read one tag per cycle ,but until now i cant let the carrier wave continuous all the time . What is happening that when the reader send a query to the tag , the tag response its RN16 ,the reader Acknowledged it ,and the tag send the ID after that the carrier wave dropped and start again with each transmission and this is a problem because  when i ran the anti- collision protocol which mean that i should send the number of slots through the query for many tags and every tag choose one slot and response back to the reader ,so i should see through the query for example 3 tag response before the new cycle start but i cant i see just one ,because the carrier wave dropped every cycle.Hope to hear from you as soon as Thanks,
Mahran 
From: ralph at schmid.xxx
To: mahran2010sawya at hotmail.com
Subject: RE: [USRP-users] Gen2 reader
Date: Thu, 4 Dec 2014 08:06:35 +0100

How exactly does this system work? Does it allow different carrier frequencies for transmitting and receiving? Ralph.  From: USRP-users [mailto:usrp-users-bounces at lists.ettus.com] On Behalf Of mahran nedal via USRP-users
Sent: Wednesday, December 3, 2014 6:51 PM
To: usrp-users at lists.ettus.com
Subject: [USRP-users] Gen2 reader Hi,Im working to implement gen 2 reader based on new generation of usrp n210 with RFX900 daughter board  to read the commercial tags. I success to read commercial tag . now i investigate to read many tags based on dynamic framed slotted aloaha , the main problem that the usrp cant continuously send the carrier wave through one cycle ,the carrier wave dropped and start again with each cycle so i cant sent many slots in each cycle because this problem . i debugging the software no problem . Is there any limitation on this hardware or daughter borad that cant support full-duplex 
 Really i need help .

Thanks,
Eng. jazi
  		 	   		  
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