Network Architecture Evolution - 1G to 4G

As we can see in the above diagram, aprt from transport technology migration from TDM to "All-IP"  LTE/4G architecture retains many similarity to 1G - AMPS Network. 

The major difference is that the Central Core (i.e. MTSO) in AMPS was handling both User and Control Planes. But in 4G they are separated to allow independent growth and modernization along with extensive reduction in "LATENCY".

LATENCY was not at all a factor during 1G or Initial 2G Periods. 

Since LTE is more of a "DATA" network and supports Voice in the form of VoIP, it provides the flexibility in using the Voice CODECS  depending upon various factors. But 2G Networks are still having a fixed rate/codec (sets) due to their radio access technology.

Eventhough GSM networks are suffering the lack of flexibility like LTE/LTE-A/3G networks, there are some steps taken by major vendors to revive this market based on the interest from existing 2G Only operators/ the ones who has a license in hand.

There are many hurdles in the form of existing 2G operator to become a LTE Operator. May be a regulatory/license obligation/business viability can halt them.

From my opinion, Voice is still going to rule for a while in the form of 2G Networks.The proof, Single Radio Voice Call Continuity (SRVCC) /VoLTE are developed not only to provide a smooth migration, also will help 4G Operators to offload all their Voice Service demand from their customers to 2G Networks.

So Technology oriented licensing which cornered the 2G Operators hsa a greater chance in reviving their business in the form tie ups with 4G Operators.

Reference :Telefónica makes first multivendor VoLTE-to-3G call handover

Reference : US Wireless Carriers Move to New Technology—for Voice

 

 

High Speed Links (HSL) & ATM Bundling

Since HSL is using ATM Bundling technology, they create one tunnel containing 30 time slots to achieve the 2 Mbps link speed. (30 * 64 = 1920) is the actual available bandwidth for the signaling traffic.

Nowadays both NSN & HUAWEI support the bundling of 8 time slots to one HSL Link. So that they can use the remaining time slots for some other purpose/links. For an example in Huawei they can map some of the incoming signaling link to another PCM without even doing any MTP3 level analysis.

Even though number of SIGTRAN deployments are growing fast, but still HSL will exist for a while till the IP-fication completes everywhere.

The traditional Narrow-band / LSL C7 Link Set capacity was 16 Links * 64 Kbps = 1024 Kbps.Where using HSL technology we can achieve a capacity of 16 Links * 1920 Kbps = 30 Mbps capacity.

APN Configurational Issues in Android OS Enabled Phones : Part-2 (End)

Refer :- Part-1

As explained in part 1 it is must to have different QoS treatment according to the type of traffic like...

• Web Browsing
• MMS
• Streaming Video
• Gaming with high level of interactive communication mode.. 

 

Figure 1 : Major Customer Segment & their preferred data services

Majority of mobile customer base using internet,blackberry, MMS & corporate VPN services. In Figure 1 I have used IBM as an example of a corporate client.

 Figure 2 : Different types of Mobile Data Services Connectivity 

Figure 2 shows that the GGSN is interconnected with MMSC, IBM Corporate network (an example), BB Server & ISP for the services respectively for MMS, IBM-VPN,BES/BIS & internet browsing.

I expect that in coming days Android OS will be able to support 11 APNs [For 2G & 3G Networks]  as per 3GPP Standard TS 24.008. So that customers and the operators can benefit from each other by introducing "blackberry" kind of OTT based services.

For an example BB phones can have different APNs for MMS,internet & BB services.If the sim is subscribed to all these services then the customer can use them without having trouble in changing any APN settings.

Since most of the operators are earning their major share of Data revenue from their corporate clients, who are using for their intranet / corporate network access using VPN, it becomes unavoidable to have this ability in most of the Android OS installed phones or Tabs from Samsung, HTC , Sony etc. More and more new handset vendors are coming in to the market with the hope using the great Android OS and making it big in the market like Samsung. So it will be a disaster in future with such phones available in the market with this known issue.


As stated by Aeneas in COMMENTS Section [ with source code references] , Android OS has the ability to support multiple APNs.But the question remains same.......

"Why Android OS enabled handsets (2G / 2G+3G) are not  configured to show the option similar like Symbian / Microsoft OS Enabled Phones ? To reduce the complexity and simplify the users experience ?  why the network interface is not optimized well in smartphones "


Conclusion : Handset manufacturers using  Android OS should take immediate action in resolving this issue.


3GPP References : TS 24.008 & TS 23.107

Comments from Friends & Critics are welcome.
  
Samsung Galaxy Y Pro Duos B5512 phone Settings :-

 

Open Queries related Mobile Telecom

 
I am searching answers and references for the following queries.This is for a thesis project. If you happen to know the answer / reference please post it in "COMMENTS" section.

Thanks to Gavin for the below answers.

1. Iu-FLEX/ A- Flex is recommended in which release of 3GPP ? 

   R5  - Refer 3GPP TS 23.236 V5.4.0 (2005-09) for Iu-Flex Covering CS + PS

   Reference : http://www.3gpp.org/ftp/Specs/html-info/23236.htm
 
2. Gb- Flex is recommended in which release of 3GPP ? 

   R5  - Refer  3GPP TS 23.236 V5.4.0 (2005-09) 

   Reference : http://www.3gpp.org/ftp/Specs/html-info/23236.htm

3. Mobile Internet Traffic Growth Graph since 1990s

    Reference : http://www.cisco.com/en/US/solutions/collateral/ns341/ns525/ns537/ns705/ns827/white_paper_c11-520862.html

4. Internet Traffic Growth Graph since 1990s 

     Reference : http://www.internetworldstats.com/stats.htm

5. ATM [Used in Iu] is part of any standard recommendations ?

     Reference : http://www.itu.int/ITU-T/recommendations/rec.aspx?rec=4560









 

EDGE Evolution - Part 4

Refer - EDGE Evolution - Part 1, Part 2 & Part 3


Multi Carrier for EDGE II

As explained in EDGE Evolution- Part-2 post , by using 

• EGPRS-2A downlink: 8-PSK+16/32QAM+Turbo Codes
• EGPRS-2A uplink: 16QAM

• EGPRS-2B downlink: QPSK+16/32QAM+Turbo Codes+Higher Symbol Rate
• EGPRS-2B uplink: 16/32QAM+Higher Symbol Rate  

So by enabling 5 Time slots we can achieve a data rate of 5 * 118.4 Kbps = 592 kbps.

Figure 1 : 2 GSM Carriers with 5+5 EDGE Capable Channels

By bringing the Mulitcarrier [ Note 1 ] concept  to EDGE II enabled GERAN Networks we can catapult the data rate from 592 to 1184 Kbps. Which is more than enough for mobile users with constant mobility and who are more interested in social networks/news/sports/mails etc. which are can be executed at the convenience of a good 1 Mbps network. This is the segment which is still untapped and the revenue growth can be achieved greatly with this big base than any other corporate/HNI  segment customers in terms of Data Services.

Note 1 :  DC-HSPA Dual Carrier standardized as part of 3GPP R8 released by 2009. Multi-Carrier HSPA Evolution by Mats Blomgren, Anders Wallén of Ericsson Research,Stockholm/Lund, Sweden



2G to 4G Technology/Architecture Evolution

Similar like the 3G to 4G  Technology/Architecture Evolution , there should be some enhancements as like Direct Tunneling & Flat Architecture as shown in the Figure 2 & 3 below.The operators gets the benefit of proper evolution path with minimum impact to customers and also the core is getting fully evolves as in SAE (EPC) standards and ready for LTE Overlaying.

Flatter architecture means some reduced latency & independent capacity enhancement in network elements.

Figure 2 : 3G to 4G Technology/Architecture Evolution 

Figure 3 : 2G to 4G Technology/Architecture Evolution

BSSAP => RANAP

Also it will be better to use RANAP protocol between BSC and SGSN [ Also between BTS & SGSN ] at a later stage.This will help to leverage the existing ready to use platforms like MME/SGW/PGW which are supporting 3G protocols already as part the 3G to 4G Evolution as shown in Figure 2.

Comments from Friends & Critics are welcome.





 

Access Control Class & Class-15 SIM Cards - Part 2

With reference to my earlier post  Access Control Class & Class-15 SIM Cards - Part 1, 

Following is the description of 3 identified usage possibilities of ACC feature in live 2G-GSM/3G-WCMDA networks.

 

Figure 1 : Commercial Usage of ACC Feature

Normally the indoor sites allotted to corporate customers in an important location of a city is good enough to serve the customers (Corp. Mainly) during 9AM to 6PM. But most of networks where I have worked, the peak busy hour starts from 5~6 PM only and lasts up to 11 ~ 12 PM.During which the indoor coverage/IBS solution capacity unnecessarily wasted.Either they will be idle / used at minimum level.

Instead those corp. customer indoor sites  should be a microcell with some external exposure. Corp. customers to have Class 15 (Example) SIM Cards. During morning hours these particular indoor sites can be configured to serve only those for CLASS-15 SIM cards.And in evening should be configured to allow all sim class. Such optimum usage will help operator to leverage those indoor BTS/NodeBs (i.e Infrastructure) . to handle those excessive  traffic at Busy Hour.

 

Figure 2 : Disaster Recovery Usage of ACC Feature

During any disaster situation in certain countries it is evident from past experiences, it will be better to cease the public communications in order to speed up the recovery actions and streamline safety of public.Also helps to prevent  unnecessary rumor based mis-behavior from public or from a particular segment of public.

So all BTS/NodeBs to be configured to serve the Class-1X which is allotted for Public Safety Organizations based on a pre-agreement.

This can be done for a particular geography/selected areas/cells in order to achieve quicker & un-interrupted recovery actions.

 

Figure 3 : Network Maintenance Usage of ACC Feature

The widely used model, doing all sort of maintenance activities like DT & Optimization etc while preventing customers from accessing the network through that particular BTS/s under maintenance and eventually avoids unnecessary disturbance to customers. 



   

EDGE Evolution - Part 3

Important Enhancements during GPRS to EDGE/EDGE II Evolution

Post the introduction of EDGE/EGPRS operators & vendors observed that the demand is further raised than the current capacity which eventually triggered the 3rd Generation Mobile telecom services roll out. But some enhancements were inevitable on existing infrastructure which are supporting GPRS/EDGE.

As part of 3GPP R4 review, Gb over IP has been inducted as part of the standards. This Ip-fication step also helps to improve the throughput capacity of Gb interface due to IP Link’s nature of flexibility in capacity growth. Additionally IP technology helps the fast processing of user data packets more efficiently in terms of speed then legacy FRAME RELAY interfaces used earlier in Gb interfaces.FR required extensive hardware and lacked the flexibility in handling growing capacity.

Post 2001, all the base stations manufactured were enabled to support EDGE II (i.e. EGERS 2A & B). Only software upgrade is required to support the Evolved EDGE.

Only handsets are needed to be upgraded to support the feature.         

Figure 1 : 3GPP R4 Standard PS Core Architecture

Figure 2 : 3GPP R4 Gb over IP

Figure 3 :BTS Support for EGPRS2 A & B

  Figure 4 : 3GPP R8 Abis over IP

When we have all the interface on IP technology and only Abis interface in traditional TDM based 2 Mbps PCM type interface, then that will be the only inefficient transport system in the network. 3GPP has already given a recommendation as part 3GPP R8 to replace that as IP technology. It took time for 3GPP to release the recommendations due to the fact that most of the networks Voice network traffic were still carried on TDM interfaces at Abis interface. Once the IP-fication thinking started to come in to picture complete IP-fication is must in Abis interfaces also to support a greater efficiency in Access Transport Network. 

It was not the BTS/BSCs capability made the delay, it was more of wait on efficient transport networks connecting them.

References : 

ETSI - A-interface over IP study Available from:

http://www.etsi.org/deliver/etsi_tr/143900_143999/143903/08.03.00_60/tr_143903v080300p.pdf

3GPP - A-interface over IP study (AINTIP) Available from:

http://www.3gpp.org/ftp/Specs/html-info/43903.htm

Development Progress of Evolved EDGE by ZTE Available from:

http://wwwen.zte.com.cn/endata/magazine/ztetechnologies/2008year/no8/articles/200808/t20080822_162092.html

Ericsson’s IP-based BSS and radio network server by Niilo Musikka and Lennart Rinnb.ck Available from:

http://www.ericsson.com/cn/res/thecompany/docs/publications/ericsson_review/2000/2000043.pdf


My Earlier posts on Evolved Edge Part-1 & Part-2 .