The focus of this paper is on a Low Duty Cycle Protocol (LDCP) recently proposed to the IEEE 802.15.4 Low Rate Wireless Personal Area Network (LR-WPAN) Task Group. The purpose is to investigate quantitatively the impact of LDCP assisted with Mediation Devices (MD) to network performance when a large number of nodes are present. A basic OPNET model of the IEEE 802.11 Independent Basic Service Set (IBSS) consisting of a number of nodes was simulated. It is found that when such an IBSS has more than 16 nodes, the system becomes unstable. However, when LDCP was applied, the total number of nodes supported by the system can be increased several times more and remains stable. Due to the lack of specific design parameters of PHY/MAC to develop a complete OPNET mo del, a simulation tool based on an Event Driven Scheduler (EDS) was developed to investigate the functionality and behavior of the Mediation Devices in a tree structured multi-hop network without considering the interlayer interactions in the protocol stack. With some simplifications, the simulation results showed the network is capable delivering packets reliably with LDCP under the constraints of high latency and low throughput. OPNET and EDS provide complimentary approaches to investigate certain aspects of statistical and deterministic characteristics of the traffic in a distributed device network. Introduction Multi-hop packet radio networks (PRN) have received research interest for many years due to their potential applications and challenges. As pervasive sensing and ubiquitous computing have been projected as the next wave of the Internet extension, autonomous device networks are being studied extensively. However, low cost and short-range wireless devices present benefits as well as challenges to adhoc network formation and maintenance, especially the mediation services in the peer-to-peer communication network. One of the fundamental issues is the impact to the communication quality and network performance due to the introduction of low-duty cycle devices. The motivation of this work is to investigate the correctness of a recent MAC proposal made to IEEE 802.15.4 LR-WPAN Task Group. The key elements include a cluster tree topology [1] and the Low Duty-Cycle Protocols running on the devices with the assistance of Mediation Devices (MD) in range [2,3]. Theoretically, collaboratively enabled LDCP does not depend on the choice of hardware architecture or network if distributed coordination is enabled. The constraint to the minimum up time is determined by the requirement of communication quality as well as the availability of the Mediation Devices in range if a certain degree of asynchronization is allowed. The IEEE 802.11 IBSS model was chosen for the following reasons. The Access Point (AP) serves as fixed MDs, which coordinate the communications among the low-duty cycle devices within its range. Any node in such an IBSS can definitely find a MD and therefore the complication due to the device range is simplified. Both IEEE 802.11 and IEEE 802.15.1 in fact addressed the issue of possible low-duty cycle commu nications based on the requirement of time bounded or regular asynchronous data services. The master/slave architecture is implemented in IEEE 802.15.1 where a basic Time Division Duplex (TDD) scheme is used to control up to seven pairs of concurrent communications in a piconet. However, by swapping slave nodes in active mode to low power modes including hold, sniff and park mode, the maximum number of slave nodes a master can manage is 255, limited by the number of node address space. The nodes in low power modes can wake up periodically and listen to the beacons from the master and resynchronize their clocks to the master. The typical communication time slot is 625 microseconds, compared to the sleep time of 1.28 seconds or more. The Distributed Foundation Wireless Medium Access Control (DFWMAC) defined by IEEE 802.11 specified two different kinds of coordination mechanisms --Distributed Coordination Function (DCF) and Point Coordination Function (PCF) --to bridge the communications among the members within a Basic Service Set (BSS) in a distributed and centralized control manner. The nodes in the “dozed” mode can wake up periodically and listen to the beacon from the access point or an ordinary node acting as a coordinator to check if there is any traffic for them. The typical beacon period within an Independent Basic Service Set (IBSS) is 0.1 seconds and the typical superframe of the beacon contains the address of senders and receivers. This paper is organized as follows. In section 2, a brief summary of LDCP is given. In section 3, the simulation results for IBSS with and without introducing the LDCP and explanations are presented. In section 4, the design of a simulation tool based on the Event Driven Scheduler (EDS) is