Reliable dissemination of bulk data is one of the important problems in sensor networks. For example, programming or upgrading the software in sensors at run-time requires reliable dissemination of a new program across the network. In this paper, we present Infuse, a time division multiple access (TDMA) based reliable data dissemination protocol. Infuse takes two input parameters:i. the choice ofthe recovery algorithm (from one of two presented in this paper) to deal with unexpected channel errors (e.g., message corruption, varying signal strength), and ii. whether a sensor should listen only to a subset of its neighbors to reduce the amount of active radio time.Based on these parameters, we obtain four possible versions of Infuse. We compare the performance of these versions to assist a designer in selecting the appropriate version based on the network characteristics. Furthermore, we demonstrate Infuse in the context of network programming.

Dependable properties such as self-stabilization are crucial requirements in sensor networks. One way to achieve these properties is to utilize the vast literature on distributed systems where such self-stabilizing algorithms have been designed. Since these existing algorithms are designed in read/write model (or variations thereof), they cannot be directly applied in sensor networks. For this reason, we consider a new atomicity model, write all with collision (WAC), that captures the computations of sensor networks and focus on transformations from read/write model to WAC model and vice versa. We show that the transformation from WAC model to read/write model is stabilization preserving, and the transformation from read/write model to WAC model is stabilization preserving for timed systems. In the transformation from read/write model to WAC model, if the system is untimed (asynchronous) and processes are deterministic then under reasonable assumptions, we show that (1) the resulting program in WAC model can allow at most one process to execute, and (2) the resulting program in WAC model cannot be stabilizing.

An algorithm for time division multiple access (TDMA) is found to be applicable in converting existing distributed algorithms into a model that is consistent with sensor networks. Such a TDMA service needs to be self-stabilizing so that in the event of corruption of assigned slots and clock drift, it recovers to states from where TDMA slots are consistent. Previous self-stabilizing solutions for TDMA are either randomized or assume that the topology is known upfront and cannot change. Thus, the question of feasibility of self-stabilizing deterministic TDMA algorithm where the topology is unknown remains open. In this paper, we present a self-stabilizing deterministic algorithm for TDMA in networks where a sensor is only aware of its neighbors. To our knowledge, this is the first such algorithm that achieves these properties. Moreover, this is the first algorithm that demonstrates the feasibility of stabilization-preserving deterministic transformation of a program in shared-memory model on an arbitrary topology into a program that is consistent with the sensor network model.

An algorithm for time division multiple access (TDMA) is desirable in sensor networks for energy management, as it allows a sensor to reduce the amount of idle listening. Also, TDMA has been found to be applicable in converting existing distributed algorithms into a model that is consistent with sensor networks. Such a TDMA service needs to be self-stabilizing so that in the event of corruption of assigned slots and clock drift, it recovers to states from where TDMA slots are consistent. Previous self-stabilizing solutions for TDMA are either randomized or assume that the topology is known upfront and cannot change. Thus, the question of feasibility of self-stabilizing deterministic TDMA algorithm where topology is unknown remains open.In this paper, we present a self-stabilizing, deterministic algorithm for TDMA in networks where a sensor is aware of only its neighbors. We derive this algorithm by systematically reusing a graph traversal algorithm. Furthermore, we also discuss the optimizations to improve bandwidth utilization and recovery from corrupted slots. Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

An algorithm for time division multiple access (TDMA) is desirable in sensor networks for energy management, as it allows a sensor to reduce the amount of idle listening. Also, TDMA has been found to be applicable in converting existing distributed algorithms into a model that is consistent with sensor networks. Such a TDMA service needs to be self-stabilizing so that in the event of corruption of assigned slots and clock drift, it recovers to states from where TDMA slots are consistent. Previous self-stabilizing solutions for TDMA are either randomized or assume that the topology is known upfront and cannot change. Thus, the question of feasibility of self-stabilizing deterministic TDMA algorithm where topology is unknown remains open.In this paper, we present a self-stabilizing, deterministic algorithm for TDMA in networks where a sensor is aware of only its neighbors. We derive this algorithm by systematically reusing a graph traversal algorithm. Furthermore, we also discuss the optimizations to improve bandwidth utilization and recovery from corrupted slots. Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

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Reliable dissemination of bulk data is one of the important problems in sensor networks. For example, programming or upgrading the software in sensors at run-time requires reliable dissemination of a new program across the network. In this paper, we present Infuse, a reliable data dissemination protocol based on TDMA based medium access layer. Although TDMA guarantees collision-freedom, unexpected channel errors (e.g., message corruption, varying signal strengths, etc) can cause random message losses. To deal with this problem, we consider two recovery schemes that use implicit acknowledgments. We also present a scheme to reduce the number of message receptions further. With this approach, sensors typically do not receive a given message multiple times. We also demonstrate that our algorithms can handle failure of sensors. Keywords: data dissemination, network programming, time division multiple access, implicit acknowledgments, sensor networks 1. INTRODUCTION Reliable data dissemination is one of the important problems in wireless networks, particularly in multihop sensor networks. For example, in sensor networks, reprogramming the network is often necessary since the sensors are deployed in large numbers and in hostile environments. Further, the requirements of a typical sensor network application (e.g., A Line in the Sand (LITeS) [1], habitat monitoring [2]) evolve over time and, hence, reprogramming the sensors after deployment is required. Towards this end, reliable dissemination of bulk data (i.e., the new program) is necessary. Challenges in reliable data dissemination. One of the important challenges in data dissemination is reliable message communication. If a sensor simultaneously receives two or more messages then they collide and all the messages become incomprehensible. Also, it is often difficult to determine whether a given message was received successfully by all its intended receivers. This is due to the hidden terminal effect, where a given message may collide at one sensor and be correctly received at another sensor. To provide reliable message communication, different medium access control (MAC) protocols are proposed. Collisionavoidance protocols like carrier-sense multiple access (CSMA) try to avoid collisions by sensing the medium before transmitting a message over the radio. If the medium is busy, it backsoff and tries to access the medium at a later time. However, CSMA offers only probabilistic guarantees about message communication. Most of the existing solutions for multihop data dissemination (especially for network programming) use CSMA protocol (e.g., [3]) and, hence, rely on mechanisms Preliminary results of this work appear as a poster in the Second ACM Conference on Embedded Networked Sensor Systems (SenSys) 2004.