Wednesday, January 28, 2009

MPLS Backhaul for LTE ?

I never read much about MPLS except for attending few classes on it in my university to get my Masters degree. But for past couple of days I am trying to understand MPLS and how can it be used as back haul in LTE. The traditional T1 lines currently used will have to fade away as the air interface bandwidth has increased from 10 Kbps to 100 Mbps, that is by 10000 folds and laying more T1/E1 lines to support such speeds in the back haul would increase the cost tremondously. So moving to ethernet is a possible solution. I first read an article whose link was published in LTE group in LinkedIn. I was pretty much fascinated by the article and it made some sense to me. Iam still trying to draw conclusions but first "how does MPLS work" is what I should be doing this weekend.
The following links would give more insights on MPLS back haul for 4G networks.
LTE and Black Sawn
Mobile Back haul for Mobile Wimax and LTE by Sprint Nextel
MPLS in Mobile Back haul Networks : Frame work and requirements

Wednesday, January 21, 2009

EPS Mobility Management and Connection Management

I was reading the spec 3GPP TS 23.401 v8.4.1 (GPRS Enhancements for E-UTRAN) today. Below is what i could make out about EPS Mobility Management (EMM) and EPS Connection Mangement (ECM).
Two states of EMM (EMM-Registered and EMM-Deregistered) and two states of ECM (ECM-IDLE and ECM-Connected) were described in the document. EMM states describe the mobility management statest that result from the mobility management procudeures e.g Attache and Tracking area update procedures.
ECM states describe the signallin gconnectivity between the UE and EPC. Definition of EMM States: EMM-De-registered : In the EMM‑DEREGISTERED state, the EMM context in MME holds no valid location or routeing information for the UE. The UE is not reachable by a MME, as the UE location is not known. EMM-Registered : The UE enters the EMM-REGISTERED state by a successful registration with an Attach procedure to either E-UTRAN or GERAN/UTRAN. The MME enters the EMM-REGISTERED state by a successful Tracking Area Update procedure for a UE selecting an E-UTRAN cell from GERAN/UTRAN or by an Attach procedure via E-UTRAN. In the EMM-REGISTERED state, the UE can receive services that require registration in the EPS.The UE location is known in the MME to at least an accuracy of the tracking area list allocated to that UE (excluding some abnormal cases).
In the EMM-REGISTERED state, the UE shall:
- always have at least one active PDN connection;
- setup the EPS security context.
Definitions of ECM States: ECM Idle : A UE is in ECM-IDLE state when no NAS signalling connection between UE and network exists. In ECM-IDLE state, a UE performs cell selection/reselection according to TS 36.304 [34] and PLMN selection according to TS 23.122 [10]. There exists no UE context in E-UTRAN for the UE in the ECM-IDLE state. There is no S1_MME and no S1_U connection for the UE in the ECM-IDLE state. ECM Connected : The UE location is known in the MME with an accuracy of a serving eNodeB ID. The mobility of UE is handled by the handover procedure.
The UE performs the tracking area update procedure when the TAI in the EMM system information is not in the list of TA's that the UE registered with the network, or when the UE handovers to an E‑UTRAN cell and the UE's TIN indicates "P-TMSI". For a UE in the ECM-CONNECTED state, there exists a signalling connection between the UE and the MME. The signalling connection is made up of two parts: an RRC connection and an S1_MME connection.

EMM State Model in UE
EMM State Model in MME

ECM State Model in UE

ECM State Model in MME

Monday, January 19, 2009

LTE vs Wimax : Myths and Realities

I was browsing through today and landed up at a discussion forum of Sprint Nextel. The post clears out the myths associated with LTE and Wimax and their convergence etc etc. The post is dated back to May 2008. The post tends towards Wimax since Sprint is largely deploying Wimax I suppose. Here are few myths and realities directly from the discussion page:

Myth: LTE is backwards compatible with 3G.
Reality: Strictly speaking, backwards compatibility implies that a 3G device can connect to an LTE base station. This is categorically not the case. LTE requires new base stations and new client devices. An HSPA handset will not be able to connect to an LTE base station, period.

Myth: LTE performance is better than WiMAX.
Reality: Because LTE & WiMAX are both based upon OFDMA-MIMO, there is not expected to be a significant performance delta over time. Because WiMAX will have been deployed commercially for over two years before the first LTE network is deployed in 2010, it may have superior performance initially.

Myth: LTE is an evolution of HSPA (3G)
Reality: The 3G evolution from WCDMA to HSPA was achieved via upgrades to operators’ existing 3G networks. LTE is not a 3G upgrade -- it must be deployed in new spectrum and requires a new radio access network (base station hardware, client devices) and connection to a new “all IP” core network (different from today’s 3G core networks.)It is possible to add LTE to existing 2G, 3G cell sites

Myth: Operators will replace their existing 2G/3G networks with LTE.
Reality: We expect operators to maintain their existing 2G or 3G networks for the foreseeable future. These networks are very efficient for voice and have built up good coverage over the years. Similar to WiMAX, LTE will initially be deployed as an overlay data network in
new spectrum. Operators will offer multi-mode handsets (e.g,. HSPA + LTE or HSPA + WiMAX) to provide the best of both worlds (coverage + high speed) to their subscribers while they build out their 4G networks over several years.

Myth: WiMAX & 3G are competitors
Reality: We expect WiMAX & 3G to be complementary. Whereas the circuit-switched voice offered by 2G & 3G networks is very efficient, WiMAX provides about 3x more data capacity than today’s 3G networks. This means operators can maintain their existing 2G or 3G network for voice & narrower-band data, and deploy WiMAX for more data intensive

Myth: WiMAX will not have as big a device selection as LTE
Reality: Even with the very first commercial Mobile WiMAX network in So. Korea, we’ve already seen a level in the variety of devices which exceeds that available for 3G today. For example, one of the most popular form factors for accessing the Wibro network are WiMAX USB
dongles with integrated MP3 players and/or storage. PC economics and innovation are backing WiMAX -- so one shouldn’t apply a traditianal “telecom” device model when comparing WiMAX & LTE. We also expect the M-Taiwan initiative and the KDDI consortium in Japan to help drive a level of device innovation not seen before for a new wireless technology.

Myth: WiMAX & LTE are going to converge.
Reality: Because WiMAX & LTE are so similar, some believe the two should converge. We’re not sure if such convergence will ever get traction, but for now, mobile WiMAX is two to three years ahead of LTE in terms of major commercial deployments and is moving full steam

The detailed post with comments can be found here.

Saturday, January 17, 2009

Apple .. Nokia .. Palm ??

I was never much of a phone lover. I always thought mobile phone was used to make calls, send texts and store phone numbers. Untill recently, when my job started demanding, I changed my mind set. I realized a smart phone would be very very help full. Well, luckily, i had an opportunity to dive into the world of smart phones. My MacBook was showing small white patch on the screen for a while now, so i thought of getting rid of it before the warranty expires...Apple is costly! So the service guy says two weeks. Anyway, the girl with whom I chat was on vacation for two weeks and I had my beautiful IPod touch at rescue, I decided to give the laptop for a LCD change.

Then i realised the beauty of smart phones and Ipod touch rocks. I could read all my mails on the go, I mean while moving from one room to other :D ... i got wifi at home so Ipod was pretty handy. The 3.5 inch screen was just amazing .. I owned this device for one and half year and i realised its beauty just recently ... all my office emails just flow to the device...web browsing is so easy and so wonderful. I could still do IM for couple of minutes...Now i want a smart phone.

I browsed a lot and i found Nokia N97 ..Palm Pre and Apple IPhone to be pretty interesting. I already use Ipod so Iphone is not what Iam looking for. More over i can run only one app in Iphone at a time. Only the email runs in the back do IM you have to open the IM app and remain there for ever which I hate. Except that i find IPhone to be very nice.

Palm Pre .. Master piece...its so beautiful. I took some time off at work and saw the entire one hour video of Palm pre from CES 09. God I love this device. It has everything i need. Multi -touch.. can simultaneously handle several apps... blah blah...its almost like desktop. A google search will result in the entire feature list of palm pre. What i hate about about the device is it comes with CDMA is not popular in India and iam not particularly interested in switching my network. And I have no idea if palm will be lauched here, I guess it will be launched.

Comming to the best...Nokia N97 ....Nokia is the most popular mobile phone maker in India. People blindly buy Nokia. N97 takes everything to next lever. It comes with 3G .. touch screen... nice keyboard.. its cool. I still dont know if it can do several apps at a time. I wish i want it to do it. Well..I have made up my mind. N97 is going to be my next phone. I have to save up for the phone, may be for three months and hopefully it will launched in India by then. And 3G would be in India soon too ...hurray!!!

My MacBook is back and i see there is a new version of ILife to download. Iam particulary impressed by iWork comaptability with Microsoft Office... I hope it works smooth....

Wednesday, January 7, 2009

LTE Interfaces and Network Elements

The following are LTE Interfaces : (Ref: TS 23.401 v 841)
  • S1-MME :- Reference point for the control plane protocol between E-UTRAN and MME.
  • S1-U:- Reference point between E-UTRAN and Serving GW for the per bearer user plane tunnelling and inter eNodeB path switching during handover.
  • S3:- It enables user and bearer information exchange for inter 3GPP access network mobility in idle and/or active state.
  • S4:- It provides related control and mobility support between GPRS Core and the 3GPP Anchor function of Serving GW. In addition, if Direct Tunnel is not established, it provides the user plane tunnelling.
  • S5:- It provides user plane tunnelling and tunnel management between Serving GW and PDN GW. It is used for Serving GW relocation due to UE mobility and if the Serving GW needs to connect to a non-collocated PDN GW for the required PDN connectivity.
  • S6a:- It enables transfer of subscription and authentication data for authenticating/authorizing user access to the evolved system (AAA interface) between MME and HSS.
  • Gx:- It provides transfer of (QoS) policy and charging rules from PCRF to Policy and Charging Enforcement Function (PCEF) in the PDN GW.
  • S8:- Inter-PLMN reference point providing user and control plane between the Serving GW in the VPLMN and the PDN GW in the HPLMN. S8 is the inter PLMN variant of S5.
  • S9:- It provides transfer of (QoS) policy and charging control information between the Home PCRF and the Visited PCRF in order to support local breakout function.
  • S10:- Reference point between MMEs for MME relocation and MME to MME information transfer.
  • S11:- Reference point between MME and Serving GW.
  • S12:- Reference point between UTRAN and Serving GW for user plane tunnelling when Direct Tunnel is established. It is based on the Iu-u/Gn-u reference point using the GTP-U protocol as defined between SGSN and UTRAN or respectively between SGSN and GGSN. Usage of S12 is an operator configuration option.
  • S13:- It enables UE identity check procedure between MME and EIR.
  • SGi:- It is the reference point between the PDN GW and the packet data network. Packet data network may be an operator external public or private packet data network or an intra operator packet data network, e.g. for provision of IMS services. This reference point corresponds to Gi for 3GPP accesses.
  • Rx:- The Rx reference point resides between the AF and the PCRF in the TS 23.203 [6].
  • SBc:- Reference point between CBC and MME for warning message delivery and control functions.
Protocol assumption:
- The S1-U is based on GTP-U protocol;
- The S3 is based on GTP protocol;
- The S4 is based on GTP protocol;
- The S5 is based on GTP protocol. PMIP variant of S5 is described in TS 23.402 [2];
- The S8 is based on GTP protocol. PMIP variant of S8 is described in TS 23.402 [2].
- S3, S4, S5, S8, S10 and S11 interfaces are designed to manage EPS bearers LTE Network elements
E-UTRAN is described in more detail in TS 36.300 [5].
In addition to the E-UTRAN functions described in TS 36.300 [5], E-UTRAN functions include:
- Header compression and user plane ciphering;
- MME selection when no routeing to an MME can be determined from the information provided by the UE;
- UL bearer level rate enforcement based on UE-AMBR and MBR via means of uplink scheduling(e.g. by limiting the amount of UL resources granted per UE over time);
- DL bearer level rate enforcement based on UE-AMBR;
- UL and DL bearer level admission control;
- Transport level packet marking in the uplink, e.g. setting the DiffServ Code Point, based on the QCI of the associated EPS bearer.
MME functions include:
- NAS signalling;
- NAS signalling security;
- Inter CN node signalling for mobility between 3GPP access networks (terminating S3);
- UE Reachability in ECM-IDLE state (including control and execution of paging retransmission); - Tracking Area list management;
- PDN GW and Serving GW selection;
- MME selection for handovers with MME change;
- SGSN selection for handovers to 2G or 3G 3GPP access networks;
- Roaming (S6a towards home HSS);
- Authentication;
- Bearer management functions including dedicated bearer establishment.
- Lawful Interception of signalling traffic.
- Warning message transfer function (including selection of appropriate eNB).
- UE Reachability procedures.
NOTE: The Serving GW and the MME may be implemented in one physical node or separated physical nodes.
Gateway General
Two logical Gateways exist:
- Serving GW (S‑GW);
- PDN GW (P‑GW).
NOTE: The PDN GW and the Serving GW may be implemented in one physical node or separated physical nodes.
Serving GW
The Serving GW is the gateway which terminates the interface towards E-UTRAN.
For each UE associated with the EPS, at a given point of time, there is a single Serving GW.
The functions of the Serving GW, for both the GTP-based and the PMIP-based S5/S8, include:
- the local Mobility Anchor point for inter-eNodeB handover;
- sending of one or more “end marker” to the source eNodeB, source SGSN or source RNC immediately after switching the path during inter-eNodeB and inter-RAT handover, especially to assist the reordering function in eNodeB.
- Mobility anchoring for inter-3GPP mobility (terminating S4 and relaying the traffic between 2G/3G system and PDN GW);
- ECM-IDLE mode downlink packet buffering and initiation of network triggered service request procedure;
- Lawful Interception;
- Packet routeing and forwarding;
- Transport level packet marking in the uplink and the downlink, e.g. setting the DiffServ Code Point, based on the QCI of the associated EPS bearer;
- Accounting on user and QCI granularity for inter-operator charging;
- UL and DL charging per UE, PDN, and QCI(e.g. for roaming with home routed traffic).
- Interfacing OFCS according to charging principles and through reference points specified in TS 32.240 [51].
Additional Serving GW functions for the PMIP-based S5/S8 are captured in TS 23.402 [2].
Connectivity to a GGSN is not supported.
The PDN GW is the gateway which terminates the SGi interface towards the PDN.
If a UE is accessing multiple PDNs, there may be more than one PDN GW for that UE, however a mix of S5/S8 connectivity and Gn/Gp connectivity is not supported for that UE simultaneously.
PDN GW functions include for both the GTP-based and the PMIP-based S5/S8:
- Per-user based packet filtering (by e.g. deep packet inspection);
- Lawful Interception;
- UE IP address allocation;
- Transport level packet marking in the uplink and downlink, e.g. setting the DiffServ Code Point, based on the QCI of the associated EPS bearer;
- UL and DL service level charging as defined in TS 23.203 6;
- Interfacing OFCS through according to charging principles and through reference points specified in TS 32.240 [51].
- UL and DL service level gating control as defined in TS 23.203 [6];
- UL and DL service level rate enforcement as defined in TS 23.203 6;
- UL and DL rate enforcement based on APN-AMBR(e.g. by rate policing/shaping per aggregate of traffic of all SDFs of the same APN that are associated with Non-GBR QCIs);
- DL rate enforcement based on the accumulated MBRs of the aggregate of SDFs with the same GBR QCI(e.g. by rate policing/shaping);
- DHCPv4 (server and client) and DHCPv6 (client and server) functions;
- The network does not support PPP bearer type in this version of the specification. Pre-Release 8 PPP functionality of a GGSN may be implemented in the PDN GW;
- packet screening.
Additionally the PDN GW includes the following functions for the GTP-based S5/S8:
- UL and DL bearer binding as defined in TS 23.203 [6];
- UL bearer binding verification as defined in TS 23.203 [6];
- Functionality as defined in RFC 4861 [32].
The P‑GW provides PDN connectivity to both GERAN/UTRAN only UEs and E‑UTRAN capable UEs using any of E‑UTRAN, GERAN or UTRAN. The P‑GW provides PDN connectivity to E‑UTRAN capable UEs using E‑UTRAN only over the S5/S8 interface.
In addition to the functions described in TS 23.060 [7], SGSN functions include:
- Inter EPC node signalling for mobility between 2G/3G and E-UTRAN 3GPP access networks;
- PDN and Serving GW selection: the selection of S‑GW/P‑GW by the SGSN is as specified for the MME;
- MME selection for handovers to E-UTRAN 3GPP access network.
GERAN is described in more detail in TS 43.051 [15].
UTRAN is described in more detail in TS 25.401 [16].
PCRF is the policy and charging control element. PCRF functions are described in more detail in TS 23.203 [6].
In non-roaming scenario, there is only a single PCRF in the HPLMN associated with one UE’s IP-CAN session. The PCRF terminates the Rx interface and the Gx interface.
In a roaming scenario with local breakout of traffic there may be two PCRFs associated with one UE’s IP-CAN session:
- H-PCRF that resides within the H-PLMN;
- V-PCRF that resides within the V-PLMN.
The functions of the H-PCRF include:
- terminates the Rx reference point for home network services;
- terminates the S9 reference point for roaming with local breakout;
- associates the sessions established over the multiple reference points (S9, Rx), for the same UE’s IP-CAN session (PCC session binding).
The functionality of H-PCRF is described in TS 23.203 [6].
Visited PCRF (V-PCRF)
The functions of the V-PCRF include:
- terminates the Gx and S9 reference points for roaming with local breakout;
- terminates Rx for roaming with local breakout and visited operator’s Application Function.
The functionality of V-PCRF is described in TS 23.203 [6].
PDN GW’s associated AAA Server
The PDN Gateway may interact with a AAA server over the SGi interface. This AAA Server may maintain information associated with UE access to the EPC and provide authorization and other network services. This AAA Server could be a RADIUS or Diameter Server in an external PDN network, as defined in TS 29.061 [38]. This AAA Server is logically separate from the HSS and the 3GPP AAA Server.

LTE Technology Suppliers

The following are LTE technology suppliers (Source : Light Reading dot com)

  • Alcatel Lucent
  • Ericsson EB
  • Fujitsu Ltd
  • Huawei Tech Co. Ltd
  • Motorola Inc
  • NEC Corp
  • Nokia Seimens Networks
  • Noretl Networks Corp
  • ZTE Corp

A comprehensive list of operators worldwide (over 100) that announced commitment to LTE and the expected deployment dates are provided by 3G Americas at

Tuesday, January 6, 2009

LTE Protocol Stack

LTE Control Plane
The control plane consists of protocols for control and support of the user plane functions:-

  • controlling the E-UTRA network access connections, such as attaching to and detaching from E-UTRAN;
  • controlling the attributes of an established network access connection, such as activation of an IP address;
  • controlling the routeing path of an established network connection in order to support user mobility;
  • controlling the assignment of network resources to meet changing user demands.

The Communication between MME and S-GW, MME and MME is taken care by GTP-C v2. This is again used to communicate with other nodes in UMTS and GERAN networks too. Eloboration soon!

LTE User Plane

Monday, January 5, 2009

Top 9 Wireless Predictions for 2009

I was browsing through the wireless blogs and I came acorss this article by Fierce Wireless dot com, where they have predicted top 9 events that "may" happen I 2009. The opening paragraph starts with disclouser saying that these pedictions are based on market research and analysis, etc etc .... Well i found first two predictions very interesting. The first prediction says "Motorola handset division will cease to be"... Now what the heck! I use a Motorola phone, I was completely surprised to read that prediction. Anyway mine a very small phone with very limited features. I like its design though, its a flap phone small and cute. Honestly i dont even know its model number. Well, I will be switching over to Nokia soon, plans are to buy Nokia N97.

Next prediction says "The end of the clamshell phone's dominance". They predict that companies will no longer be interested in making small handset with flip feature. But in india where a person below poverty line use a phone, i doubt this trend. Small phones are very much required in india and companies get most of their revenue from there. I was always a fan of flip and slide phones. The big slide phone used in The Matrix is my all time favourite. You finish talking on the phone and hit the silde with other hand to pust it in, and the sound it makes ..aah..awesome. Lets see what 2009 is going to be. Here are the rest of the predictions.

Prediction 1: Motorola's handset division will cease to be - 2009 Predictions
Prediction 2: The end of the clamshell phone's dominance - 2009 Predictions
Prediction 3: Tier 2 and Tier 3 U.S. carriers will become scarce - 2009 Predictions
Prediction 4: Low-cost carriers will experience a resurgence - 2009 Predictions
Prediction 5: Palm will not survive the OS wars - 2009 Predictions
Prediction 6: Cox will launch wireless but traction with consumers will be limited - 2009 Predictions
Prediction 7: All-you-can-eat plans will drop in price - 2009 Predictions
Prediction 8: Wireless broadband pricing will decline - 2009 Predictions
Prediction 9: App stores will start to compete with each other for downloads and - 2009 Predictions

Another wonderful blog

My thrust for knowledge and couple of google searches landed me into a nice blog written by Michael Mice. You can find very interesting articles in there about web, wireless, entertainment and computing, thats what the blog description says. Anyway if you look at the top right side of the blog you will find a link called "Stop Flying Blind" which will land you into a book in progress by Mike. I guess the link gets updated with new chapter as he proceeds. But right at this moment when you click the link, it talks of "14. How to segment the market for a new product" which i found very interesting. Being naive to my job (one and half year experience is considered less) and my company currently working on entering new market segments, i found the chapter very informative. Though i couldnt read the chapter completely (Iam saving it for sunday evening tea), but first few paragraphs were amazing. The following is the direct quote from that chapter.

"If you design a product to please everyone, chances are you’ll end up with inoffensive pablum that excites no one. That works pretty well in politics, where voters have only a couple of choices. But in new product design, where consumers can choose from an almost infinite range of new products, unexciting is usually deadly. So you should optimize the product to make one segment of customers deleriously happy, and not worry about the rest.Unfortunately, segmenting the market for a new type of product is a lot harder than you might expect"

I guess our top management has done enough market research before thinking of entering the new segment. And once Mike is done with his book, I will buy two copies of the book for sure, one for me and one for my big boss :D .

LTE Architecture

The above picture captures my interest zone in LTE. The three tables show the protocols which I am currently interested in. The goal is to implement a small LTE prototype excluding the radio interface.

LTE handoff

I was reading LTE specs for a while now. I am more interested in core network of LTE. Well, iam an IP guy so my interests are in EPC. The pic below describes the LTE handoff scenario where source eNodeB knows the target eNodeB. I with my friend tried to simulate some LTE request responses. We are more interested in control plane signalling. So we picked up this call flow, removed the air interface portion and wrote a small client server programs for the rest.

This particualr call flow has both X2 and S1 interface control plane signalling. So after reading the X2AP(TS 36423-840) and S1AP(TS 36413-840) protocol specs for hours, i could finally figure out the packet structures. Then, we had to figure out SCTP stack. Since all the controlling is done on SCTP. Some google search and some test programs told me that Linux kernel version 2.6 and above have SCTP stack built in. I got the lksctp stack from source forge, complied the kernal and zoom. God, I love linux. Well you can get SCTP for Mac too and i got it in my mac. Thanks NKE SCTP!

Well we had everything in hand, SCTP sockets up and running, S1 AP and X2AP request response packets and nice ubuntu and mac pc's to write and test scripts. After couple of hours of colourful C, we had our test programs ready. Hurray!! Below is what we implemented

Next aim to implement GTP-U header!! Will take some time and lot of reading. Office is pretty relaxing these days, might help in speeding up things.

Sunday, January 4, 2009

Sun Sparc fumes!!

I recieved a beautiful 5 year old Sun Sparc box couple of days back. After a fight for more than a month, the box was shipped from our US office to India. I was suppose to do some automation on it. Once i got the box, i opened it, nicely placed it on the table and plugged in the power supply and boom. The SMPS of the box blew. I dint notice a small switch indicating the voltage rating. It was set to 110 volts and in India is 240 volts. What an Idiot i was!! Its sure a rocket science to find that switch. Any way , i will have very good time running behing IT guys to fix the box. I dont know if any local hardware vendors could fix the box. Hope for the best!!!
What a way to begin monday morning!! huh!!

Saturday, January 3, 2009

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Friday, January 2, 2009

New Blog to My List

I was browsing about 3G 4G today, well i do it everyday and i landed up at a beautiful blog by Martin Sauter. He is a telecom researcher, consultant, book author and off-course a blogger based in Europe I suppose. He had written some wonderful blogs about wireless in there. Well, office was not that busy today and i could squeeze in couple of hours to read his entries. I was particularly overwhelmed with one of his post where he described all the events related wireless which happened in 2008.

Next i went on reading about LTE, which is my hot favourite these days. I am reading about X2 and S1 interfaces of LTE. Good news is that me and my friend have come with a small program which performs a handoff signalling in LTE. Its a very basic simulation. How ever we are happy that we implemented it over SCTP transport. I will post more about it soon.

I was never much into phones and stuff. I own a ipod touch , which is just brilliant. I always thought phones were just meant for talking and messaging. Just recently i have changed my mind. I had a look at Nokia N97 today. The very first look of it made me go crazy. I decided then and there, it is going to be my next phone. Well i need to wait for couple of months before i squeeze in budget for that, hopefully i will do it.

And with a beautiful kiss, movie, "The Mummy" comes to an end in HBO and i feel like lying on my bed now.

Welcome All

I had been blogging for some time now , but i always thought of making a record of everything I learn. So as a new year resolution i decided to blog about my reading and learning experiences

This blog is all about what I am currently doing, my job experiences, problems which i face with my work, latest from the wireless market and so on. 3G,4G, Wimax and WLAN are my areas of interest and my emphasis would be on them.

In the links section (see right side) you will find bunch of links which i follow. My source of knowledge would come from there. I am very thank full to the owners of the links for sharing the information. I will not directly copy paste the information from there, but will try to make my own conclusions out of them. Kindly consider that this information is for my personal record, I might be wrong in some cases and i would be very thank full if you correct me. Comments are always welcome.

Thanks --Santosh Kumar Dornal