DEVS/NS-2 Environment: An Integrated Tool for Efficient Networks Modeling and Simulation

Abstract

This paper presents a new DEVS/NS-2 modeling and simulation environment which supports both high and low levels of abstraction for network m odeling and sim ulation. DEVS (Discrete Even t System Specification) is a welldefined m athematical f ormalism specif ication for structure and behavior of dynamic system s. The NS-2 is a discre te event network simulator, whose primary use is intended to build and run various detailed network m odels and protocols such as TCP/IP, satellite links, and wireless networks. By combining the two powerful modeling and simulation systems, the significant benefits attained by the interoperabl e sim ulation of DEVS and NS-2 are reduction of the cost, increased hi gh and low level m odeling power, and enhanced r eusability. To integ rate the sys tems seam lessly, two major challenges are add ressed. The firs t cha llenge is to synchronize the different ways of handling event schedules by th e two simulation system s. This paper illustrates h ow the s imulation tim e advances of DEVS and NS-2 are synchronized with each other. The latte r problem is related to assign ing the appropriate level of model structure and behavior within the combined system. The details of low level ne twork with protocol and com ponent description is m odeled by NS-2 while DEVS serves as controller by modeling the high level behavior (e.g. us e case scenario bu ilder) of target network m odels and interaction of the as sociated actors. In this paper, we take two exam ples of wireless sensor netw orks. The first exam ple is to describe our approach to the de velopment process for m odeling and simulation in DEVS/NS-2 environm ent, and the purpose of the second example is to show how DEVS/NS-2 environ ment is ef ficient f or m ilitary system applications. Th is exam ple is extended to dem onstrate an effective way to m ake a decision on the appropria te level of sensor node' s behavior. This leads to the disc ussion of trad eoffs between energ y efficiency and effectiveness of decision making for the sensor network. The advantages and at BALL STATE UNIV on November 19, 2014 dms.sagepub.com Downloaded from the disadvantages are d iscussed in the last part of this paper by com paring DEVS/NS-2 environm ent with its r elated studies such as DEVS BUS and OPNET.

DEVS modeling of mobile wireless ad hoc networks

“…Recently there has been some work for integrating tools such as NS-2 and DEVS simulators [37,38] with DEVS. In [37] the authors show how to implement heterogeneous simulators based on the DEVS Bus concept, showing how to integrate DEVS models, NS-2 models and a TCP simulation using the HLA as middleware.…”

“…In [37] the authors show how to implement heterogeneous simulators based on the DEVS Bus concept, showing how to integrate DEVS models, NS-2 models and a TCP simulation using the HLA as middleware. In [38], the author shows how to integrate DEVS and NS-2 using the DEVS/C++ simulator. We believe such integration would allow DEVS/Cell-DEVS models to make use of already built libraries in such simulators and would increase their applicability while reducing their development costs.…”

Extending DEVS to support multiple occurrence in component-based simulation

“…Let us consider for example the case of coupling DEVS models with Network Simulator (NS) models, as investigated in (Kim 2006). Assume that we want to establish a communication between two users A and B through a communication component (as discussed earlier in the example of section 2), but this time using a model simulated by NS.…”

DEVS simulation of peer-to-peer file-sharing

“…This includes advanced network-level models: work has been done to integrate a DEVS simulation engine with the popular network simulator NS-2 [13], and a recent project has also appeared to build a pure DEVS network model library [27].…”