We propose a novel channel management algorithm, called distributed load balancing with selective borrowing (D-LBSB), for cellular mobile networks. As an underlying approach, we start with a fixed channel assignment scheme where each cell is initially allocated a set of local channels, each to be assigned on demand to a user in that cell. The novelty of our D-LBSB scheme lies in handling the hot cell problem because it proposes to migrate unused channels from suitable cold cells to the hot ones through a distributed channel borrowing algorithm. With the help of a Markov model, the probability of a cell being hot and the call blocking probability in a cell are derived. Detailed simulation experiments are carried out in order to evaluate our proposed methodology. Performance comparison reveals that the D-LBSB scheme performs better than a centralized version in an overloaded system, and significantly better than several other existing schemes in terms of call blocking probability, under moderate and heavy loads.

We propose an optimistic quality-of-service (QoS) provisioning scheme for multimedia traffic in wireless networks. The scheme uses the standard classification of network traffic into two priority classes based on their bandwidth requirement and delay tolerance. We classify the users as local or departing based on their current coordinates in the cell. A call admission algorithm, a call management algorithm and a prediction based resource reservation algorithm which reserves the specified bandwidth (by borrowing channels from neighboring cells, if required) in the predicted destination cell(s) of a departing user are presented. A novel approach called bandwidth compaction is proposed which enables more efficient spectrum utilization. Simulation experiments show improvements of about 24% in the call blocking probability and 12% in the connection dropping probability over other bandwidth reserving schemes. An overall improvement of 24% in bandwidth utilization over other schemes not employing any bandwidth management technique, is also observed.

We propose an efficient dynamic load balancing scheme in cellular networks for managing a teletraffic hot spot in which channel demand exceeds a certain threshold. A hot spot, depicted as a stack of hexagonal 'ring' of cells, is classified as complete if all cells within it are hot. The rings containing only cold cells outside the hot spot are called 'peripheral rings'. Our load balancing scheme migrates channels through a structured borrowing mechanism from the cold cells within the 'rings' or 'peripheral rings' to the hot cells in the hot spot. For the more general case of an incomplete hot spot, a cold cell is further classified as cold safe, cold semi-safe or cold unsafe, and a demand graph is constructed from the channel demand of each hot cell from its adjacent cells in the next outer ring. The channel borrowing algorithm works on the demand graph in a bottom up fashion, satisfying the demands of the cells in each subsequent inner ring. Markov chain models are developed for a hot cell and detailed simulation experiments are conducted to evaluate the performance of our load balancing scheme. Comparison with an existing load balancing strategy under moderate and heavy teletraffic conditions, shows a performance improvement of 12% in terms of call blockade by our load balancing scheme.

We propose a dynamic load balancing scheme for the channel assignment problem in a cellular mobile environment.As an underlying approach, we start with a fixed channel assignment scheme where each cell is initially allocated a set of C channels, each to be assigned on demand to a user in the cell.A cell is classified as 'hot', if the degree of coldness of a cell (defined as the ratio of the number of available channels to the total number of channels for that cell), is less than or equal to some threshold value, h.Otherwise the cell is 'cold'.Our load balancing scheme proposes to migrate unused channels from underloaded cells to an overloaded one.This is achieved through borrowing a fixed number of channels from cold cells to a hot one according to a channel borrowing algorithm.A channel assignment strategy is also proposed based on dividing the users in a cell into three broad types -'new', 'departing','others'-and forming different priority classes of channel demands from these three types of users.Assignment of the local and borrowed channels are performed according to the priority classes.Next, a Markov model for an individual cell is developed, where the state is determined by the number of occupied channels in the cell.The probability for a cell being hot and the call blocking probability in a hot cell are derived, and a method to estimate the value of h (threshold) is given.Detailed simulation experiments are carried out in order to evaluate our proposed methodology.The performance of our load balancing scheme is compared with the fixed channel assignment, simple borrowing, and two existing strategies with load balancing (e.g., directed retry and CBWL), and a significant improvement of the system behavior is noted in all cases.Pennission to make digital/hard copies of all or part of this material for personal or classroom usc is granted without fee provided that the copies are not made or distributed for profit or commercial advantage, the copyright notice, the title of the publication and its date appear, and notice is given that copyright is by permission of the ACM, Inc.To copy otherwise, to republish, to post on servers or to redistribute to lists