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Jean-Samuel Najnudel - BJT PARTNERS SARL jsn at bjtpartners.comHi Alexander, On 7/3/12, Alexander Chemeris <alexander.chemeris at gmail.com> wrote: > Hi Jean-Samuel, > > On Tue, Jul 3, 2012 at 10:59 PM, Jean-Samuel Najnudel - BJT PARTNERS > SARL <jsn at bjtpartners.com> wrote: >> Hi Alexander, >> >> Thank you very much for your e-mail. >> >> 1/ They did not started the PCB manufacturing yet. They are still >> waiting for my feedback on the questions I asked to Andrey. >> >> Actually, if we need to replace the SRAM and/or the flash to use >> cheaper equivalent components, we may need to reroute the PCB. This is >> why I ask them to wait for the feedback from Andrey before starting >> the PCB production. They can start as soon as we let them know what we >> do about the SRAM and the flash (with or without PCB files update). >> >> Anyway, I was not very worried about the delay. As discussed together >> last time in Paris, before deploying the UmTRX on the field, we would >> need OpenBTS to support handover. Even for tests, if I open the >> network without handover, because of the terrain in Mayotte, there >> will be so much call drops nobody in Mayotte will accept to use our >> network anymore in the future. Really, handover is very important in >> Mayotte. >> >> As I understand OpenBTS is under development but it is quite hard >> work. It will probably not be ready before the end of this summer. >> This is why I did not feel very worried about the PCB production >> delay. > > We really need to get prototypes ASAP for many reasons - we have to > start certification process, we still need to find enclosures, we have > other pilots pending, etc. And every week of delay is painful for us. Ok. I will ask the fab to start the production ASAP. > >> Anyway, I will do my best to get the UmTRX prototypes ready as soon as >> possible. I just need a feedback from Andrey because, if it does not >> lower the UmTRX board performances, we should really try to find an >> alternative solution to use cheaper SRAM and flash chips. This could >> improve a lot the cost structure of the UmTRX. > > We should be fine with this chip: > http://www.digikey.com/product-detail/en/IS61NLP51236-200TQLI/706-1103-ND/1557418 > (with no PCB changes). This looks good. However, this SRAM is 18 MBits instead of 36 MBits. This makes a quite big difference. Are you sure this will be fine ? Andrey, do you confirm this is fine ? Is this chip fully pin compatible ? > >> 2/ I did not contacted Lime yet but I will do this as soon as >> possible. I will do my best to get the LMS chips on time. >> >> By the way, for both PCB assembly and LMS order, how many UmTRX board >> would you like the fab makes ? We discussed together about 5 or 10 >> units but we did not took the final decision yet. It can be any >> reasonable number between 5 and 10. Please let me know the quantity >> you would need. I will ask the fab and order the component quantities >> we need. > > We have only 5 FPGAs left, so I think we should assembly 5 prototypes. > I.e. we need 10 LMS chips. This is fine for me. I will do this. > > But we could safely order more PCBs, because we're pretty sure PCB won't > change. Yes, for sure I will. You are completly right. I asked for the price. There is only about 100 Euros difference in total between 5 and 20 PCB. Moreover, ordering 20 PCB will save us a lot on next batches. It will also save us a lot of valuable time if we need some more prototypes. Actually, the PCB is what makes the production quite long. Anyway, I ask the fab will move toward the production asap. Best regards. Jean-Samuel. :-) > >> By the way, the meeting with the fab this morning was fine and they >> are ready to start the production asap. > > Please, start PCB manufacturing ASAP. > > -- > Regards, > Alexander Chemeris. > CEO, Fairwaves LLC / ООО УмРадио > http://fairwaves.ru >