Sunday, December 04, 2005

Links...

HSDPA validation project
Xavier Dubois's Homepage
Research project
UMTS Forum

Reason

I think why the result of simulation using the UMTS extension did not match the result of simulation using regular ns-2. I set the bandwidth at the core network too big and this did not create any bottleneck.

Friday, November 25, 2005

links...

Click here

real time and non-real time traffic

I confused when the result of two different simulation are not similar. i'm simulating real time traffic and non-real time traffic using UDP contant bit rate (CBR) and exponential respectively.The first simulation is done using the eurane extenstion to ns-2. In this extension, users are allow to create additional nodes (i.e. ue, bs and rnc) that are not defined in the original ns-2. The second simulation is done using the normal nodes defined in the orignal ns-2. For both simulation, I created 2 user equipments, 1 node b, 1 rnc, 1 sgsn, 1 ggsn, 2 nodes, 2 sinks Loss Monitor to measure the UDP bandwindth in Mbit per second. I created a bottle neck between sgsn and ggsn.

The result of the second simulation shows that the the real time traffic will suffer from mixing with non-real time traffics in the link congestion. The result of first simulation does not show any of that. I have set the same bandwidths between each duplex links for both simulation. Is it something do to with sink Loss Monitor or am I not tracing at the correct location?

I'm interested in measuring the throughput at the bottleneck link between sgsn and ggsn.

Anyone has come across any journals or literatures simulating real time traffic and non-real time traffic using UDP?

I got a reply:

The SGSN and GGSN in EURANE are just normal NS-2 nodes. If you placed
the bottleneck there then both simulations would be effected in a
similar way. However the effects of this bottleneck may be negated by
the high throughput possible with the HS-DSCH channel. Without knowing
the data rates of the traffic, and the channel model used for the
HS-DSCH, its difficult to say.

/Neill

Monday, November 21, 2005

Poisson simulation parameters


$Exponential1 set rate_ 384Kb
$Exponential1 set packetSize_ 210
$Exponential1 set burst_time_ 500ms
$Exponential1 set idle_time_ 500ms
$Exponential1 attach-agent $udp1


Is this correct? need to check..hehe

I found a website in order to emulate the poisson process set the burst_time_ to zero.

ns patch for gcc 4.0

Click here

I managed to do a simulation for best effort which consists of real time and non-real time data using UDP protocol. I'm trying to enhanced the script by finding the right simulation parameters.

Sunday, October 16, 2005

UMTS Architecture

According to TS 23.101 :"General UTMS Architecture"

UTMS architecture are split to user equipment domain and infrastructure domain.

User Equipment Domain
In layman's term, user equipment is a mobile phone which is to access the infrastructure through the air interface. Air interface is the air space between the mobile phone and the base station.

Infrastructure Domain
It consist of UMTS Terrestial Radio Access network (UTRAN) and core network.

UTRAN
UTRAN is the access network where the user equipment interact with Node B trough the air interface. "The Access Network Domain consists of the physical entities which manage the resources of the access network and provides the user with a mechanism to access the core network domain." The Technical document explained that Access Network Domain which also known as UTRAN consist of the physical entities. Physical entities in UTRAN are the Node B and Radio Network Controller (RNC).

Core Network
"The Core Network Domain consists of the physical entities which provide support for the network features and telecommunication services. The support provided includes functionality such as the management of user location information, control of network features and services, the transfer (switching and transmission) mechanisms for signalling and for user generated information."

patching...

To patch ns2.28 with umts module. First, download the patch from the EURANE website and ns2.28 from ns2 webiste. Untar the eurane patch and ns2.28. In the ns-2.28 directory type patch -p1 < ~/{patchfilename.diff} . After patching is completed, type ./install in the ns-allinone-2.28 directory. Update ns path in bashrc.

Reference

1.

Saturday, October 15, 2005

umts links

Click Here...
A tutorial page on how to install ns on cgywin.

Thursday, October 13, 2005

Ubuntu vs NS2

I found a guide how to install NS2.28 on Ubuntu. Ubuntu is a Live CD distro where user just pop the cd in the cdrom and start using the OS on booting without any installation. It runs on your computer's Ram. Click Here for the link.

Wednesday, October 12, 2005

Running through my mind...

I have some questions:-

1. How much bandwidth should I allocate to simulation model to simulate the RAN?
2. What is the packet rate?
3. How do I know that the simulated model is efficient with reference to the normal model?
4. How to proof the modified model is better than the current model?
5. Where can I find the parameters for the current diff serv model for RAN?
6. How do I transform that parameters so that I can use to simulate the model?

Found a new url today. Click here

Null

The null policy is use when all the incoming traffic in the physical queue is put in the a virtual queue without metering and policing.

Saturday, September 24, 2005

WFQ Url

Anybody looking for WFQ discipline for DiffServ. Go to Alexander Sayenko's website and download the patch. This patch is for ns2.28 and older. I wonder where i can find the documentation or some examples so i can use the WFQ in my ns script.

Wednesday, September 21, 2005

Url

Sergio Andreozzi did a master thesis to verify the real experiment conducted in a real DiffServ-enabled IP network with Network Simulator (NS2). He developed and improved the NS2 DiffServ Module and contributed to NS2 community

"The goal of nsBench project is to develop supporting tools that enable creating, analyzing and visualizing NS-2 simulation scripts and traces automatically.nsBench is a drag-and-drop GUI and easy to use in undergraduate and graduate networking courses. nsBench makes NS-2 simulation development and analysis faster and easier for students and researchers without losing the flexibility or expressiveness gained by writing a script."

In other words, users feel like using HTML editor and it is easy to use. User still to have to understand tcl script in order to do the simulation.

Tuesday, August 02, 2005

i'm back

Aloha, it's been a while. I'm back. I hope i can start blogging again.

Wednesday, February 23, 2005

New...

New module...

I'm now in the new module, 1 week and 14 weeks to go...

I'm registering for transmission and switching and broadband communication

Wednesday, February 09, 2005

Hijrah...

Selamat Menyambut Awal Muharam.

Sunday, February 06, 2005

CNY...

After 3 months of studying, I've completed my 2nd modules(finish my exams). 2 modules more to go. The third module will start on the Valentine's Day after one week of holiday. I'm looking forward this third module. I want to work really hard and excel in the third module. My instinct tells that I'm beginning to see what should I do in attaining my goals. All the best to myself. Make sure your spirit is up every time and anywhere. Let makes this year a succesful one.

Happy Chinese New Year!

Friday, February 04, 2005

Study...

LEsson learned today.Continue wHat ever You have started.. Never look back. All it needs is some patience and effort.

Wednesday, February 02, 2005

Mixed Feeling...

So the interview is confirmed on Friday. I have mixed feeling about the interview. Suddenly, I felt so scared...God Help me

Saturday, January 29, 2005

Laptop...

I want a laptop....hehehe...
Just finished my first paper today...another one paper to go...

Thursday, January 27, 2005

Saturday...

Saturday will be a big day for me...Optical Communications.. Yikes

Monday, January 17, 2005

Update...

My interview was postphoned on one tentative date. The reason was that my future boss who is going to interview me will be going on business trips. Phew, I glad the interview was changed. It gives me some load off for next week. I got an extra class tommorow night. Any tips for job interview? If somebody stumbled upon this blog...hahaha

Saturday, January 15, 2005

Interview...

I was called for an interview from company. Wish me luck. GOod Luck!

Thursday, January 13, 2005

2 weeks...

Aiyoh...2 weeks more...

Friday, January 07, 2005

The Count Down...

Three weeks before the exam starts...

Monday, January 03, 2005

New Year...2005

I want to wish a Happy New Year 2005. My condolence to all the tsunami's victims.