Das Signal wrote: > Thank you for this update. Have you considered the use of an indoor > directional antenna (such as a couple cheap yagis)? It could provide > the necessary boost required to reach the meeting place you mention.
Thank you for the great idea! I knew about directional antennas, but my original line of thinking was to do the most with omnidirectional first, i.e., deploy a combo of amplifier+omnidirectional first and see how it performs, and then possibly go directional. But thanks to your suggestion, I now see that it would make more sense to try the directional antenna approach first, before going for the amplifier - if nothing else, for cost reasons: the amplifier would be a hefty investment at $2600, whereas directional antennas are way more affordable. Onward to specific directional antenna types - here are two that I found: https://excel-wireless.com/product/1850-1990-mhz-yagi-antenna-17-dbi/ https://excel-wireless.com/product/1850-1990-mhz-grid-parabolic-antenna-20-dbi/ Yesterday I spoke to an RF engineer at my day job, and he told me that the parabolic antenna would probably work better than the Yagi for my application. What do you think? Note that if I go with any kind of "big" antenna (like either of the above, as opposed to little antennas that screw directly onto SMA connectors on the back of sysmoBTS 1002), I will have just one antenna for both DL and UL. I already have a Sysmocom cavity duplexer for PCS band (the one they sell in their webshop, the indoor version with SMA connectors), and I know that I will need to keep all 3 coax cables (two between the BTS and the duplexer, and one between the duplexer and the antenna) as short as possible. Denver wrote: > There are some carriers that will let you send SMS PDUs, if I understand what > you mean. Normally this is done via SMPP. The carrier that we at JMP use > (Bandwidth) has given us SMPP access, and we could setup a test environment > for you if you're interested in seeing if it does what you want. I am interested - but not right this moment. Would it be possible to revisit this discussion a little later - say, maybe a few weeks from now? There is some significant homework which I will need to do on my own before I get back into all this SMPP etc discussion and test setups: 1) In my worldview, voice calls come first and SMS is an addition to voice telephony, not a replacement - voice first, SMS second, in this order. For this reason, I would like to get voice calls working properly first, including outside connectivity, beyond just the minimal internal-switch-only MNCC built into OsmoMSC. Here the main homework for me will be getting Asterisk installed and running on my Slackware server (I decided to try Asterisk first, before others), getting it to work with BulkVS SIP trunks (their service is so cheap that it will cost me next-to-nothing to use them for this test bed, and I figure it will be a good learning exercise even if I end up going with someone else in the end), and then connecting my GSM network to this beast via osmo-sip-connector. 2) Once I get voice calls working to my satisfaction and I am ready to move on to SMS, I will start with some tests on the extant T-Mobile GSM network, to see if SMS transfer from one T-Mobile GSM subscriber line to another really is as transparent as I imagine, or not quite - seeking a reference point here. 3) I will need to study the existing implementation of SMPP in OsmoMSC (yay for FOSS with study-able source code!), to get a better idea of how GSM-to-SMPP SMS interfacing has already been done by people with more experience than me. Only after I do all of the homework listed above, only then I will be in the right shape to continue this SMS discussion on an intelligent level, and only then I will be ready to accept your offer of a test setup. M~ _______________________________________________ Community mailing list Community@freecalypso.org https://www.freecalypso.org/mailman/listinfo/community
