Thanks Marcus Müller , Marcus D. Leech , Activecat. yes , we can call this "Ethernet to wireless bridge using GSM RF channel ". I have some questions, please :
1- Can I use both UDP source & TCP source in this way : Can I connect output of" UDP source" & output of "TCP source" to input of "Socket PDU " and connect output of "Socket PDU " to the input of the "PDU to tagged stream " block ? What is wrong in this connection ? 2- But when I connect the output of TCP or UDP source to the Socket PDU , I got an error ! what does the Socket PDU block take as an input?! 3- Also when I connect output of "TCP or UDP source" to "PDU to tagged stream " I got an error , what must be the input of the PDU to tagged stream block ?! Does the "PDU to tagged stream " is used here instead of the "stream to tagged stream" block and has same role? 4- Does the block " Socket PDU" can be used instead of a socket ? It don't understand what is the importance of this block ? 5- Is there any flags so that when signaling packets are coming (SIP or ARP) : TCP source is enabled while UDP source is disabled ? And the inverse happens when there is RTP packets coming? Note that , in network settings in Twinkle soft phone , there is a port number for RTP different from port number of SIP & we can change these ports numbers , I don't know if this may help me . 6- Do I have to write a code for socket ?or simply I can write ,in the "UDP source" block in Gnu radio(2nd lap) , the IP address & port number of the Ethernet connection (of 2nd lap) receiving from Twinkle(1st lap) ? 7- If there is no new packets coming , I want to send zeros instead of repeating the sent packets ? How Can I do this ? i.e: I want to insert 8 bits zeros after each ofdm symbol as a guard band : I tried to insert " pad source " block to do this , after the IFFT block and before the cyclic prefixer block , but it is not allowed to connect 2 inputs to the cyclic prefixer also I don't know how to use the pad source to insert these zeros & I don't know if there is a block to concatenate between the zeros coming from the pad source & the output of the ifft block . Thanks in advance . 2014-06-20 7:42 GMT+03:00 Activecat <active...@gmail.com>: > On Thu, Jun 19, 2014 at 9:32 PM, Sara Chérif <saracheri...@gmail.com> > wrote: > >> Sorry , I forgot to say that some packets coming from Twinkle are SIP & >> ARP packets not only RTP. >> Hence , I think I need to receive RAW packets in GNU Radio ( as I have >> different type of packets: RTP , ARP , SIP packets) >> >> Note that : >> I use 4 laps & 2 USRPs. >> 1st & 4th lap has twinkle softphone & I will make a call between them. >> 2nd lap has an OFDM TX implemented by Gnuradio. >> 3rd lap has an OFDM RX implemented by Gnuradio. >> First and 2nd laps are connected by Ethernet cable. >> 3rd & 4th laps are connected by Ethernet cable. >> One USRP is connected to the 2nd lap , the other USRP is connected to the >> 3rd lap. >> 2nd lap(GNUradio ,ofdm tx) will receive the packets from 1st >> lap(Twinkle) using RAW socket (as I think ) . >> 2nd lap will send the packets to the 3rd lap by the USRPs. >> 3rd lap ( Gnuradio , ofdm rx) will send real time voice packets to 4th >> lap (Twinkle) using RAW socket(as I think). >> >> > Hi Sara, > > What you need is only a wireless bridge. > A wireless bridge allows you to connect one network (1st and 2nd lap) to > another (3rd and 4th lap) over the airwaves (which is USRP-to-USRP), rather > than having to run wire from one room (2nd lap) to another (3rd lap). > I would say you only need to work at the OSI layer 1 (physical layer). In > this case you can ignore the UDP, RTP etc as far as gnuradio is concerned. > > In alternative you may implement the wireless bridge using 802.11, but it > is not mandatory for you to work at OSI layer 2. > > So you may rephrase your question as "how to build wireless bridge using > USRPs ?" > Then you may want to work in either transparent "repeater" mode or > "bridge" mode. In either case you don't need to work at layer 3 or above. > The basic requirements are just that, you need the USRPs to setup wireless > link at full-duplex, and make sure the bandwidth of the wireless channel is > sufficient for few concurrent VoIP calls. > > Anyway, I may be wrong. >
_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
