Research On Location-Aware Buffer Management In Mobile AD Hoc Networks

In recent years, with the development of wireless communication technologies and mobile intelligent terminal, as well as the LBS application, research on location-aware MANET network where sending messages to a specific area by adopting multi-copy replication mode, has received widespread attentions. But it brings many problems:First, most policy forwarding decision depends on sharing the history information between nodes, so it may not be applied to the scenario where the privacy or record maintenance cost are very limited; Secondly, Uncontrolled and bind coping cause huge network overhead; Besides, most of the existing buffer management mechanisms for multiple-copy replication mode are not comprehensive enough. There is certainly room for improvement in some aspects, e.g., buffer queue scheduling, duplicate number control and redundant copies cleaning.This thesis mainly focuses on investigating the factors that impact the message dissemination under the scene of location-aware MANET. By combining these factors, we present the IBMP (Integrate Buffer Management Policy) to alleviate some problems in multiple-copy replication mode. The IBMP mainly consists four algorithms, namely Location-Aware Forwarding Queue Scheduling (LFQS), Location-aware Message Replacement Algorithm (LMRA), Adaptive Copy Control Algorithm (ACCA) and ACK-based Redundancy Clean-up Algorithm (ARCA). The concrete research content is as follow:1) The moving characteristic of mobile nodes while moving among regions in the given scene is analyzed, the influence of the access frequency, moving direction and access interval time toward the node trajectory prediction is discussed. Then the average probability of message delivery is proposed.2) According to the propagation characteristics of multiple-copy replication mode, the copy exponent is employed to represent the duplicate number of a single message in the network. Then the LFQS algorithm is introduced to schedule the message queue to be forwarded by taking consideration of both the delivery probability and duplicate number of the message. When a buffer overflows, expect utilizing the message delivery probability, we also consider the spread speed and size of the message when proposing the LMRA algorithm.3) In order to control the duplicate number of a single message and remove the redundant copies in time, we allow every node to maintain a list of the delivered message and propose the ACCA algorithm and the ARCA algorithm based on this list.4) Through extensive simulations, the result demonstrates that IBMP can to some extent improve the performance of the multiple-copy replication mode, e.g., delivery rate, latency and network overhead.