Re: Question about ms max power parameter.
Hello Andreas, set ms max power to 0 to get 1 milliwatts to start with (rach and initial power). set it to 30 to get 1 watts (1800) or 33 to get 2 watts (900). during dedicated channel, it is up to the bts to change the power level up or down, depending on the uplink level/quality. Thank you very much for your hint. I have set it to 0 dBm now and it works fine. I have my phones directly next to the BTS so i think it will not raise the power above 1 or 2 mW. regards. Philipp
Re: Question about ms max power parameter.
Hi Sergey Does this setting has linear dependence? Or is there something like a calibration table for max_power_red value? I think i can answer this (please correct my if i am wrong). To my understanding nominal power is the maximum power the BTS is capable to transmit. In the case of the nanoBTS it is 23dBm which is about 200mW. So the nominal power is the calibration value you asked for. The max_power_red value is the setting for the actual output power. In my case it has been set to 20dBm. This should result in an output power of 23dBm-20dBm=3dBm=ca. 2mW. This is the default setting. I do not know if it is the lowest possible setting. I transmit into a dummyload anyway which results into a cell radius of approx 1m. The dBm scale is not linear, just look it up yourself It's easy ;-) regards. Philipp
Re: Question about ms max power parameter.
Dear Sergey, On Thu, Apr 11, 2013 at 01:13:39AM +0400, Sergey V. Efimov wrote: Does this setting has linear dependence? Or is there something like a calibration table for max_power_red value? dB values are never linear, they're logarithmic. dBm is vs. Power. The value is the absolute tranmission power of the MS (uplink) in dBm. It has nothing to do with max_power_red, whcih is about the relative reduction of downlink transmit power respective to the nominal transmit power of the BTS in downlink. The values are all specified in the relevant GSM specs. -- - Harald Welte lafo...@gnumonks.org http://laforge.gnumonks.org/ Privacy in residential applications is a desirable marketing option. (ETSI EN 300 175-7 Ch. A6)
Re: Question about ms max power parameter.
dexter wrote: My question is how low may i set ms max power level? Is 15dBm already the lowest possible minimum or can i set it down to 1dBm if i like? hi, set ms max power to 0 to get 1 milliwatts to start with (rach and initial power). set it to 30 to get 1 watts (1800) or 33 to get 2 watts (900). during dedicated channel, it is up to the bts to change the power level up or down, depending on the uplink level/quality. regards, andreas
Re: Question about ms max power parameter.
Hello Andreas, Does this setting has linear dependence? Or is there something like a calibration table for max_power_red value? Thanks, Sergey. On Apr 11, 2013, at 12:20 AM, Andreas Eversberg wrote: dexter wrote: My question is how low may i set ms max power level? Is 15dBm already the lowest possible minimum or can i set it down to 1dBm if i like? hi, set ms max power to 0 to get 1 milliwatts to start with (rach and initial power). set it to 30 to get 1 watts (1800) or 33 to get 2 watts (900). during dedicated channel, it is up to the bts to change the power level up or down, depending on the uplink level/quality. regards, andreas
Re: Question about ms max power parameter.
Hi, On Tue, Apr 09, 2013 at 10:57:38PM +0200, dexter wrote: in the openbsc.cfg i find a parameter ms max power which is set to 15 dBm (apporox 30mW) by default. http://openbsc.osmocom.org/trac/wiki/osmo-nitb_VTY says the following: maximum transmit power (in dBm) to be used by MS in this BTS. This is used in the System Information on the BCCH as well as for the MS power level at the time a dedicated channel is activated. My question is how low may i set ms max power level? Is 15dBm already the lowest possible minimum or can i set it down to 1dBm if i like? I'd say it's 0..40. Kind regards, -Alexander Huemer [?] http://openbsc.osmocom.org/trac/wiki/osmo-nitb_VTY#msmaxpower0-40 [?] http://cgit.osmocom.org/openbsc/tree/openbsc/src/libbsc/bsc_vty.c#n1934
Re: Question about ms max power parameter.
On Tue, Apr 09, 2013 at 10:57:38PM +0200, dexter wrote: in the openbsc.cfg i find a parameter ms max power which is set to 15 dBm (apporox 30mW) by default. http://openbsc.osmocom.org/trac/wiki/osmo-nitb_VTY says the following: maximum transmit power (in dBm) to be used by MS in this BTS. This is used in the System Information on the BCCH as well as for the MS power level at the time a dedicated channel is activated. My question is how low may i set ms max power level? Is 15dBm already the lowest possible minimum or can i set it down to 1dBm if i like? I just looked it up. GSM 05.05 speaks of values 0..39dBm, although the underlying thing is the 'Power control level', MS_TXPWR_MAX_CCH, which has a range of 0..31. This is also mentioned in GSM 05.08. I also found [1]. Kind regards, -Alexander Huemer [1] http://gsm-optimization.blogspot.com/2012/04/mstxpwrmaxcch.html
Re: Question regarding timeouts and RRLP
Hi Alexander Holger, thank you for the link, I will bookmark it, and sorry for the same message. Thank you for the help Holger, I will look at it this week, I might have then a few more questions. Best regards, Refik On Wed, Apr 4, 2012 at 6:38 PM, Holger Hans Peter Freyther hol...@freyther.de wrote: On 04/04/2012 04:40 PM, Refik Hadzialic wrote: Dear group members, Hi Refik, osmo-nitb (libmsc/) keeps a channel open by reference counting. This counting is implemented by the 'transaction' or 'operations'. See gsm_subscriber_connection for 'operation' pointers. So what roughly happens is: 1.) A channel is opened, a dummy operation is created to not immediately close the channel 2.) Whoever feels responsible creates an operation/transaction.. 3.) When a transaction is done msc_release_connection is called.. 4.) when all transactions and operations are completed the channel will be released. You would probably want to add a new operation
Re: Question regarding timeouts and RRLP
Hi Refik, On Wed, Apr 04, 2012 at 04:40:36PM +0200, Refik Hadzialic wrote: (I would like to apologize if you got this message for the second time, but last time I sent it to the wrong mail address and I am not sure if the gnumonks mailing list is synchronized with this one, osmocom, I am sorry if you get this mail for the second time!) That's very easy to check. http://lists.osmocom.org/pipermail/openbsc/2012-March/003727.html Kind regards, -Alexander Huemer
Re: Question on characteristics of nano-BTS
Thanks for your feedback on this Paul. I have had some more feedback from another chap who was also very helpful. I'll post it on this thread to assist anybody searching for this type of information in future. I will certainly let you know how the application proceeds. ... Yes you need to state 1800Mhz (class of emission) The BTS is a single-TRX BTS designed for indoor use (–5C to +45°C). Maximum transmit power is +23dBm for the 1800 MHz BTS Channel Spacing is 200Khz Power output control is 12 steps Power consumption is 13watts Standards are ETSI EN301489-9 Using the tool at http://www.compeng.com.au/emc_conversion_tables_power_calculator.aspx you should be able to work out what you require knowing the max output is +23db As a rough guide (as I'm NO radio expert) the formula is like so: EiRP (dBi)=ERP (dB)+2.1 ERP(dB)=Ant Gain (dBd)+POWERBTS (dBm)-Combiner loss-Cable loss-Fading margin So Output power = 23db Unit lose = 6.5db per 100m Gain of anntena = 10db Combiner lose = 3db Fading Margin = 2db Radiated power of attenna (ERP) = 21.5db (23 - 6.5 + 10 - 3 - 2) Max radiated power (EiRP) = 21.5 + 2.1 = 23.6dbi On 26/10/2011 13:51, Paul Dart wrote: Hi, On 26 October 2011 11:16, Alex J Lennonajlen...@dynamicdevices.co.uk wrote: Hi, I'm working through a UK Ofcom Non-operational license application form to obtain a license to test with an ip.access nano-BTS 1800. I'm having a little trouble determining a few of the characteristics of the nano-BTS and I wonder if anybody could offer me any advice? - Presumably I can provide GSM 1800 as the frequency of operation (or do I need to be more specific?). For the purposes of Ofcom this should be fine. They will then give you a set channel/freq. in that band to use and this will be specific. - What would be the class of emission designation for UK GSM ? - Given I'm just going to use a nano-BTS with a couple of Wifi 10dBi SMA antennae is there somewhere Wifi antennas are usually tuned for 2.4GHz and 5.8GHz (maybe 900MHz if you get it from the US or something). You are probably better getting an antenna that will work properly in the band you are using (unless it's a wideband antenna). I can find figures for: - peak RF Power supplied to the antenna or load? - peak radiated power (ERP or EIRP) - mean radiated power (ERP or EIRP) You need to know: a) the power output of the nanoBTS you have (ask the manufacturer/check the datasheet) b) any cable losses between that and the antenna c) the gain of the antenna (I presume 10dB is at 2.4GHz for wifi. It will likely be less for 1800MHz, see my comments above). Add these together and you will get the power out. a) and b) gives you the answer to the first one. ERP and EIRP are subtly different. Check wikipedia/ask Ofcom if you need some help. Many thanks, Alex Hope this helps, and good luck. Let me know if you do get an approved application as I would be interested in doing the same in the UK. Regards, Paul
Re: Question on characteristics of nano-BTS
Hi, On 26 October 2011 11:16, Alex J Lennon ajlen...@dynamicdevices.co.uk wrote: Hi, I'm working through a UK Ofcom Non-operational license application form to obtain a license to test with an ip.access nano-BTS 1800. I'm having a little trouble determining a few of the characteristics of the nano-BTS and I wonder if anybody could offer me any advice? - Presumably I can provide GSM 1800 as the frequency of operation (or do I need to be more specific?). For the purposes of Ofcom this should be fine. They will then give you a set channel/freq. in that band to use and this will be specific. - What would be the class of emission designation for UK GSM ? - Given I'm just going to use a nano-BTS with a couple of Wifi 10dBi SMA antennae is there somewhere Wifi antennas are usually tuned for 2.4GHz and 5.8GHz (maybe 900MHz if you get it from the US or something). You are probably better getting an antenna that will work properly in the band you are using (unless it's a wideband antenna). I can find figures for: - peak RF Power supplied to the antenna or load? - peak radiated power (ERP or EIRP) - mean radiated power (ERP or EIRP) You need to know: a) the power output of the nanoBTS you have (ask the manufacturer/check the datasheet) b) any cable losses between that and the antenna c) the gain of the antenna (I presume 10dB is at 2.4GHz for wifi. It will likely be less for 1800MHz, see my comments above). Add these together and you will get the power out. a) and b) gives you the answer to the first one. ERP and EIRP are subtly different. Check wikipedia/ask Ofcom if you need some help. Many thanks, Alex Hope this helps, and good luck. Let me know if you do get an approved application as I would be interested in doing the same in the UK. Regards, Paul
