On Friday, an open source group released software that cracks the A5/1 encryption algorithm used by some GSM networks. Called Kraken, this software uses new, very efficient, encryption cracking tables that allow it to break A5/1 encryption much faster than before.

The software is a key step toward eavesdropping on mobile phone conversations over GSM (Global System for Mobile Communications) networks.

In December, the group released a set of encryption tables designed to speed up the arduous process of breaking A5/1 encryption, but the software component was incomplete. Now the software is done, and the tables are much more efficient than they were seven months ago.

…. Read more of the original article at ComputerWorld.

• TR-10-466 Emission Measurments of a Cellular and PCS jammer at a Prison Facility – http://www.ntia.doc.gov/osmhome/contrabandcellphones/NTIAPrisoncelljammerreport_TR_10_466.pdf
• 10-468 Inital Assessment of the potential impact from a jamming transmitter on selected in-band and out-of-band receivers – http://www.ntia.doc.gov/osmhome/contrabandcellphones/NTIATechnicalMemorandum_10_468.pdf

Much of this is just marketing spin to promote systems that in some cases do not even meet the 4G standard.

There’s less to 4G than meets the eye, and there’s little reason for people to scramble for it, at least for the next few years…..

Read the full original article at the Associated Press.

More information:-

• ‘4G’ technologies do not officially exist – yet – Mobile Business Breifing

Although some wireless/cellular operators and vendors have already been using the term “4G” for their LTE and WiMAX services, the “true” specifications for 4G services developed by standards organization 3GPP  will be published in March 2011 under Release 10, according to current targets.

Read more of the original article at Total Telecom

While breaking the security takes time, the approach theoretically leaves GSM more directly exposed to call interceptions and other threats. Most cellular carriers still use the lower-grade GSM quality (A5/1) as their base calling technology, but 3G/UMTS (the upgrade to GSM) uses Kasumi and is potentially exposed as well.

More information:- http://www.emergentchaos.com/archives/2010/01/another_week_another_gsm.html

Chinese network equipment vendor Huawei’s challenge to European rivals has largely focused on its pricing advantage, but industry experts say it now has another key selling point; the quality of its technology.

As the telecom industry emerges from the global economic slump, European telecommunication gear companies – global market leader LM Ericsson Telephone Co., Nokia Siemens Networks, a joint venture between Finland’s Nokia Corp. and Germany’s Siemens AG, and Paris-based Alcatel-Lucent SA – are likely to face increased pressure from world no. 2 Huawei Technologies Co. in their own back yard.

…. read the rest of this article at Total Telecom

Estimates have suggested that as many as 25 million handsets were being used without an IMEI number. This has decreased over the past few months with the operators offering a reprogramming service to insert a valid IMEI into the handsets, but it is thought that there are still millions of potentially illegal handsets in use.

Mobile phones without an IMEI are typically low-end handsets from smaller Chinese phone manufacturers who cut costs by skipping the IMEI programming stage.

Although the serial number does not affect the billing, which is managed by SIM identities, it does add an extra layer of proof for the police if checking who made a phone call from a specific handset. The issue became a serious topic after such phones were allegedly used by terrorists, and the lack of unique IMEI made it impossible to prove who made or received specific phone calls as they couldn’t be traced to a specific handset.

A ban on importing handsets without unique IMEI’s was imposed earlier this year.

Requests to reduce tower numbers are becoming more common, and the article led me reflect on tower issues I have come across.

1. Over the years many operators have merged. Each company originally had it’s own towers, and mergers have left companies with towers next to each other. The Indonesian government has stepped in and made companies start to remove excess towers.
2. The Brazilian government was concerned about too many towers, so mandated no new towers were allowed in certain areas.
3. As operators load up towers with additional antennas, many are finding the towers are not meeting MTBF specifications due to accelerated rusting or poor construction. Both weight and wind loading can be problems. Many installers I have spoken with mention they can feel the towers move under their own weight.
4. One client was recently considering removing antennas due to excess weight on the tower from the microwave dishes used for back haul. They were using two 2G BTS on each sector, and combining them would have resulted in 3dB loss  in both uplink and downlink. (Additional antennas would have to be added eventually when 3G was installed, thus not really fixing the problem.)
5. Sharing towers can introduce interference and Passive Intermodulation (PIM) problems.

With the race to roll-out 3G, tower issues are an ever increasing headache for operators, with many 3G BTS units in a heavy tower mounted format, which also require the mounting of additional antennas (increasing wind loading problems).

There are three common configurations operators can utilize for rolling out 3G, but each comes with its own advantages and disadvantages.

Option A – GSM and 3G on same feeder and antenna

Used by Telstra in Australia, this system uses existing antenna and feeder infrastructure, which reduces cost, weight and wind loading issues.

A high roll-off filter is used to combine the 2G and 3G systems at the BTS end of the feeder.

For this configuration to work,  particular attention must be paid to the construction quality and Passive Intermodulation in the feeders. The system must have very low PIM, making the system “technology transparent”.

Option B – GSM and 3G on separate feeder and antenna

The 2G and 3G systems utilize different feeders.

Costs are increased by having to run new feeders and mount new antennas, also increasing wind loading significantly.

Passive Intermodulation is less of a problem using separate feeders, but the operators can still have PIM interactions between the systems.

Option C – 3G tower mounted BTS

The 2G utilizes existing feeders, while a tower mounted BTS (normally connected by fiber optic) is used for 3G with an additional set of antennas.

The costs are lower, but both weight and wind loading are significantly increased.

Passive Intermodulation is less of a problem using separate feeders, but the operators can still have PIM interactions between the systems.

Conclusion

Requests to reduce tower numbers will only become more common in the future. As operators add more infrastructure to existing towers, weight and wind loading will begin to be problems.

There are several configurations that can be adopted by operators, but one solution does not fix all the problems. Instead the operator needs to approach each installation individually to determine the best solution.

More articles:-

• Govt Calls for shared Network Towers – 20 Nov 2009
• Rajasthan Bans New Mobile Towers Pending Review – 8 Dec 2009

The two initial courses added are:

• XC001 – Intro to Radio Waves – An introduction to  radio waves and their characteristics.
• XC002 – Intro to Cellular – An introduction to cellular technologies and protocols.

The courses are provided in Flash and PDF format. Each course is supplemented with a set of PDF lesson notes.

Additional courses will be made available on this list regularly.

GSA says that 95% of WCDMA networks have enabled HSPA, with HSPA mobile broadband services now commercially available on 283 networks in 119 countries. There are an estimated 150+ million HSPA subscribers worldwide says GSA, with more than half of commercial HSPA networks are capable of peak downlink data speeds of 7.2 Mbps or higher.

Read more of this article…..