Before, we could start compiling the programs, we had to translate the compiling script from csh to bash. However, after the upgrade of the bash shell in the departmental machines, we could use the originally compiling script files with several minor changes due to the changes of OS environment.

NEVOT 3.32 is the latest released version. Therefore, we decided to start with this version. There are several modules of NEVOT: nevot, netutil, gsm, tk and tcl. In order to install NEVOT 3.32 successfully, we have to install the following library packages:

With NEVOT 3.32 alone cannot be executed. There are 2 other applications have to be installed in order to execute and test NEVOT. They are PMM and ICC.

Because NEVOT was originally developed in Solaris, there are many codes required to be modified in order to fit into the compiler and environment in Linux. In order to modify the codes, we had to understand the functionality of the module, the flow of the program and the effects of those changes. Fortunately, the modifications are not very complicated and there was no need to re-write a large portion of the source code at this stage.

Different packages may require different versions of tcl/tk and other libraries mentioned above. Therefore, the number of packages required is greater then we mentioned above. As many of the library packages are not included in the NEVOT 3.32 packages and are old versions, much time were spent on finding them. We have tried to use the updated versions. However, many of them are 1) not backward compatible, or 2) developed specifically for the previous version of other libraries.

After it was successfully compiled, we found that it did not work at all in Linux environment. Having serious consideration and taking different consultation, we would expect the time spent on modifying the source codes maybe too long. Therefore, we managed to compile the latest version NEVOT 3.35, which is not released yet.

To compile NEVOT 3.35, there also a list of pre-required packages as shown below:

This time, fewer libraries were required and much of the experience gained in the porting of the previous version can be applied. Although most of the libraries used in the last time could not be reused in here and those libraries required to be searched for and installed again, the progress is smoother and faster in this case.

In this version of NEVOT, ICC was not used anymore. Instead ISC, Integrated Session Controller, was used as the conference controller. There are 2 libraries that were used in ISC which go with the Solaris OS but not with Linux. They are libservers libresparse. Although these libraries have been found and compiled under Linux, their compatibility remains a question.

In the current status, the NEVOT 3.35 is about 90% ready. However, the progress has an obstacle that there is a compatibility problem of BLT 8.0 in Linux. There is a problem in the program but there is no obvious reason to support that it is a problem specific to NEVOT and the coding of the program. It seems that it is the problem of the language or the library itself. There is still no obvious idea of how to solve it nor any straight forward solution for it.

Much of the time and effort has been spent due to the inter-operability and inter-compatibility of the various kind of libraries. Many of the libraries packages were developed by different people at different time. The compatibility of different libraries packages is the greatest problem in this project. The portability and development time of NEVOT can be greatly increase if it can be developed in an integrated environment. Since most of the problem seems to come from tcl/tk, we can translate those portion of codes into Java and remain the other modules which concern with the hardware and device drivers to C.

The compiled NEVOT 3.32 package is stored in /proj/dcc/marconinet/rleung/nevot

The compiled NEVOT 3.35 package is stored in /proj/dcc/marconinet/rleung/nevot-335

The executable programs for NEVOT and PMM can be found in

The ISC can be found in /proj/dcc/marconinet/rleung/isc

The source codes are in /proj/dcc/marconinet/rleung/isc/src

The executable program is in /proj/dcc/marconinet/rleung/isc/bin

The required libraries are in /proj/dcc/marconinet/rleung/isc/lib

The purpose of the measure is to measure the effect of the distance between the transmitter and the receiver to the bandwidth of the WaveLan transmission. Two notebooks running Linux were used to setup a private network and no other transmission was being made except those made by these 2 machines. One of the machine stayed in a fixed location and acted as a base station while the other one acted as mobile user and was placed in different location for measurement. We would like to analyze the influence of different location in our campus on the air interface, such that we can find the optimum points in order to place the wireless LAN base stations in order to construct a wireless LAN in our Morningside Campus.

A program called hop_speed was used to carry out this experiment. It gives out 2 bandwidth readings, v_i and v_i’. The bandwidth was measured based on an algorithm similar to the one that is being used in Bing (by Beyssac, P. 1995) and Pathchar (by Jacobson, V. 1997).

Dan Duchamp and Neil F. Reynolds, Measured Performance of a Wireless LAN, Computer Sicence Department, Columbia University.

Henning Schulzrinne, Guide to NEVOT 3.28, GMD Fokus, Berlin, June 17, 1995.

Henning Schulzrinne, NEVOT Implementation and Program Structure, GMD Fokus, Berlin, February 9, 1996.