Investigate mobility protocols and devise methods to characterize and improve their performance; assist industry in developing standards for seamless and secure mobility.
More publications....
ANTD has developed free NS-2 modules for download as part of our work with IEEE 802.21 and the IETF. More information is available here.

Nada Golmie
Emerging and Mobile Network Technologies Group

Seamless Mobility

Contributions to standard developing organizations


---- 2009 ---- ---- 2008 ---- ---- 2007 ---- ---- 2006 ---- ---- 2005 ---- ---- Other presentations ----

Contributions to Standard Developing Organizations (SDOs)

---- IETF ----
Date Meeting Name Format
July 2007 69th Chicago, IL Performance Evaluation of L3 MIH Transport pdf ppt
---- IEEE 802.11 ----
Date Number Name Format
November 2006 11-06-1581-00-000w Proposal-selected-psuedo-code-in-lb88 pdf doc
---- IEEE 802.19 ----
Date Number Name Format
January 2007 19-06-0044-02-0000 Organizing Matrix for Coexistence pdf doc
---- IEEE 802.21 ----
Date Number Name Format
September 2005 21-05-0358-00-0000 Parameter_Effects_on_Performance pdf doc
January 2006 21-05-0419-00-0000 Performance measurements for Link Going Down Trigger pdf ppt
March 2006 21-06-0524-01-0000 802_16_Parameter_Effects_on_Handover_Performance pdf ppt
May 2006 21-06-0598-05-0000 QoS Proposal pdf doc
May 2006 21-06-0614-00-0000 MIH_Handover_scenarios pdf ppt
July 2006 21-06-0687-01-0000 QoS support pdf ppt
January 2007 21-07-0011-0001 QoS Updates pdf doc
May 2007 21-07-0182-0001 Transport Protocol and State Machine pdf ppt
July 2007 21-07-0268-0000 Performance Evaluation of L3 MIH Transport pdf ppt


Release information

A simulation platform based on NS-2 is being developed in order to leverage publicly available modules for several wireless and wired technologies. IEEE 802.3 (Ethernet), IEEE 802.11b (WLAN), IEEE 802.15.1 (Bluetooth), and UMTS have been developed for various previous releases of NS-2, but have not been integrated to run jointly in a single simulation environment. By integrating various modules into a single platform, we make it possible to simulate heterogeneous environments that incorporate a variety of access networking technologies.

  • 10/01/2006: release of the IEEE 802.16 model developed for NS-2.
  • 01/23/2007: release of the mobility package developed for NS-2.
  • 02/28/2007: update of mobility package. TCL scripts have been udpated according to new model.
    Use the request form to download the file.
  • 04/30/2007: update of the IEEE 802.16 model.
    Note: contains patch for ns-2.31. See documentation for the list of modifications.
    Use the request form to download the file.
  • 10/04/2007: update of documentation (version 1.2) for the IEEE 802.16 model.


Description of software modules

  IEEE 802.16 module Mobility extensions
Overview An overview of the model is given in the following presentation  
Installation The release file available for the IEEE 802.16 module for NS-2 contains instructions to install the module. Instructions for installing the mobility package for NS-2.
User and design information The IEEE 802.16 model documentation describes the available features, the TCL configuration, and design aspects of the implementation. word icon pdf icon
A description of the IEEE 802.16 package classes pdf icon
Updates and bug fixes
  1. Problem: Duplicate variable declarations
    The variable "Packet *pktBuf_;" is declared in both mac802_16.h and mac802_16SS.h
    Solution: remove the declaration in mac802_16SS.h
  1. Problem: MAC 802.11 stalls after scanning
    In certain situations, the MAC 802.11 will lock its transmission after a scan.
    Solution: add the following code in your mac-802_11.cc on lines 3852 and 3915:
    &nbsp&nbsp&nbsp //resume transmission
    &nbsp&nbsp&nbsp if (mhBackoff_.busy() == 0 && mhDefer_.busy() == 0 && mhSend_.busy() == 0) {
    &nbsp&nbsp&nbsp tx_resume ();
    &nbsp&nbsp&nbsp }
  2. Problem: Error message during compilation:
    hsntg/nd.cc: In constructor `NDAgent::NDAgent()':
    hsntg/nd.cc:127: error: call of overloaded `bind(const char[17], uint32_t*)' is ambiguous
    Solution: The error may occur depending on the version of gcc used.
    Replace bind("prefix_lifetime_", &prefix_lifetime_); with bind("prefix_lifetime_", (unsigned int*) &prefix_lifetime_);

Frequently Asked Questions (FAQs)

IEEE 802.16 model for NS-2
  1. Q: What does "bash: ns: command not found" mean?
    A: The NS-2 simulator is not properly installed/compiled. Execute "./configure; make clean; make" from the ns-2.29 directory.
  2. Q: What does invalid command name "Phy/WirelessPhy/OFDM" while executing "Phy/WirelessPhy/OFDM set g_0" mean?
    A: The OFDM class is unknown to NS. This means the code has not been recompiled. Execute "./configure; make clean; make" from the ns-2.29 directory.
  3. Q: What does invalid command name "Mac/802_16" while executing "Mac/802_16 set debug_ 0" mean?
    A: The Mac/802_16 class is unknown to NS. This means the code has not been recompiled. Execute "./configure; make clean; make" from the ns-2.29 directory.
  4. Q: Compilation error "NeighborEntry already defined".
    A: A class with the same name is defined in the diffusion3 subdirectory. Rename the class NeighborEntry to WimaxNeighborEntry where used.
    Note: The updated pre-release contains the modification.
  5. Q: Does the current model support class of service (UGS, RTPS, NRTPS and BE)?
    A: No. Though the architecture defines the structures to use it, the current scheduler does not make use of it.
  6. Q: What scheduler is implemented?
    A: The scheduler allocates downlink bandwidth first according to pending traffic. Next, the contention periods are allocated in the uplink bandwidth. The rest of the uplink bandwidth is then allocated to one MS (The MS is picked in a Round Robin fashion). Currently the BS does not consider bandwidth requests from the MSs.
  7. Q: How to set the -DDEBUG_WIMAX switch?
    A: Look for the line starting with "DEFINE = -DTCP_DELAY_BIND_ALL" and add the -DDEBUG_WIMAX.
  8. Q: How to set the datarate?
    A: Unlike the 802.11 implementation, the datarate is not something set in TCL. Since each burst can use a different modulation and therefore have different datarates, we opted for a dynamic calculation of the datarate. By setting the frequency bandwidth, cyclic prefix and the modulation, the datarate will change. The scripts located in tcl/wimax/datarate/ show the maximum throughput achieved with frequency bandwitdh of 7MHz.

Mobility package for NS-2

  1. Q: The scripts are not running in the pre-release dated 01/27/07. What is the problem?
    A: The model is under development. Therefore some older scripts may not have been updated. Download the new release with udpated examples.
  2. Q: How do I install the mobility package?
    A: The mobility package contains a complete ns-2.29 directory. Delete the default ns-2.29 directory and replace it with the one provided in the compressed file.
  3. Q: Segmentation fault when using older scripts with the new model.
    A: The structures have changed for the MAC and classifer classes. The scripts have to be updated.