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[pdf] ECC Report 249 - Unwanted emissions of common radio systems: measurements and use in sharing/compatibility studies - Apr 2016
"The scope of this report is:

 To compare the measured characteristics of a limited number of equipment samples with the existing regulatory limits in order:

 To explore the current definitions of the limits used for the OoB and spurious domains given in ITU-R Recommendations and ETSI standards

 To compare the "safety-net" worst case characteristics of OoB emissions in Rec. ITU-R SM.1541 [1] and the measurements of the equipment samples

 To compare spurious domains emissions in ERC/REC 74-01 [2] Rec. ITU-R SM.329 Category B and the measurements of the equipment samples

 To characterise the unwanted emissions of various digital modulation technologies of broadband communication systems. It considers the boundary between the out-of-band (OoB) and spurious domains as well as the levels of unwanted emissions in a set of measurements on equipment samples.

 To develop possible concepts to better characterise the unwanted emissions of broadband systems using digital technology to enable a more efficient use of the radio spectrum in adjacent bands."

"It is observed that the measured emissions are typically lower than the limits in
recommendations and ETSI standards by a significant margin of several tens of dBs in the spurious domain,
except for the harmonic frequencies. This finding has an important implication for sharing and compatibility
studies which are typically based on the assumption that equipment would only just meet the limits set out in
standards. "

"Two questions are raised:

1 Should sharing/compatibility studies be based on typical performance of unwanted emissions rather than the limits?

2 Should those limits/levels in bands adjacent to the operating one (and boundary between the OoB and spurious domains) be redefined or be re-considered on a case-by-case basis to better reflect actual performance of equipment, and therefore allow for increased opportunities for sharing/compatibility and more efficient use of spectrum in future?"

"Regarding the out-of-band domain limits, the measurements have shown that the limits specified in ETSI standards are generally the relevant limits particularly tailored to the specific application; ITU-R SM.1541 [1] (containing only the "safety-net" limits which are mainly only based on services) consequently shows a large margin as expected."
ECC  CEPT  reports  spectrum-sharing  interference  *  resources  OOBE  spurious-emissions  LTE  DAB  GSM 
march 2018 by pierredv
Hacker Spoofs Cell Phone Tower to Intercept Calls | WIRED Jul 2010
"A security researcher created a cell phone base station that tricks cell phones into routing their outbound calls through his device, allowing someone to intercept even encrypted calls in the clear."
Only works for 2G GSM
SDR  cellular  IMSI-catchers  Stingray  Wired  GSM  hacking 
august 2016 by pierredv
“GSM Whitespace” technology now being tested in Mexico - PolicyTracker May 2015
"Technology that promises to allow the use of GSM networks as a secondary service in spectrum bands already assigned to uninterested operators is currently being tested in Mexico." Based on research by Shaddi Hasan, a computer science PhD student at the University of California, Berkeley
PolicyTracker  GSM  whitespaces 
may 2015 by pierredv
GSM Evolution can benefit from GSM 900 MHz installed base - PolicyTracker Nov 2014
"There are several pieces of work being studied for the Internet of Things (IoT) within the cellular standardisation body, the 3GPP. A few months ago, PolicyTracker reported on competition between the LTE-M approach, which is now a work item in 3GPP TSG RAN, and the "clean slate" approaches to IoT, which are currently being studied in 3GPP's GERAN specification group." "In order to become a 3GPP standard, an initiative has to graduate from being a study item to a work item. Traditionally, 3GPP requires four companies to support an initiative for it to become a work item. PolicyTracker understands that Nokia Networks supports GSM Evolution but is focussing its cellular IoT efforts on the LTE-M programme. Whether GSM Evolution can become a work item in time for 3GPP Release 13 is unclear." "There was consolidation among advocates for a clean slate approach to the IoT in September as telecoms giant Huawei acquired UK-based Neul for a sum that PolicyTracker understands to be in the r"
OtT  GSM  Ericsson  900MHz  LTE-M  3GPP  GERAN  Nokia  Qualcomm  Neul  Huawei 
november 2014 by pierredv
Small cells in the enterprise: private GSM comes to City Hall (pdf) - Small Cell Forum case study, Zaanstad
Private GSM network hanging off the PBX. Special case: Netherlands has opened up some of its GSM 1800MHz spectrum so anybody can transmit
Small  Cell  Forum  case  study  small-cells  GSM  1800MHz  Netherlands 
may 2014 by pierredv
Tracking down wideband interference - Land Mobile 20th August 2012
"Two troublesome interference problems which are affecting GSM-R railway communications in the UK – and in other countries which employ the GSM-R radio standard – have been pinned down in a report compiled for Network Rail by wireless experts at Red-M, now a part of Affini. Their work builds on an earlier study carried out by Red-M for Ofcom." Talks about narrowband/broadband interference; one fix is to improve receiver selectivity.
GSM-R  cellular  Vodafone  railroads  GSM  OOBE  receiver  filtering  LTE  interference  O2  Ofcom  receiver  selectivity 
april 2013 by pierredv

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