混合多點跳躍與蜂巢式網路上轉送服務動態定價之研究

Abstract

混合多點跳躍與蜂巢式網路整合了蜂巢式網路與多點跳躍網路兩者的特性，在近幾年受到愈來愈多的注意，而提供適當的回饋以鼓勵無線網路節點提供轉送資料的服務是此種網路得以成功運作的重要因素。目前相關的研究大部分都是採用固定費率的方式，以節點所轉送的封包數目或資料量來決定回饋的多寡，這種方式無法有效反應無線網路變動頻繁的特性。本研究針對混合多點跳躍與蜂巢式網路上的轉送服務提出適當的回饋定價機制，同時考慮轉送成本與服務可獲得性。首先，以網路上有效節點數的多寡來決定提供轉送服務的回饋價格，希望在達到網路業者利潤最大的同時也能兼顧服務可獲得性。接著，本研究也利用每個節點所在位置對服務可獲得性所具有的不同貢獻度為基礎來給予不同的回饋價格。此研究所提出的定價機制將部分回饋從重要性較低的節點移轉到重要性較高的節點，藉以激勵重要性高的節點提供轉送服務的意願，如此可在不增加轉送成本的情況下提高整體網路的服務可獲得性。此外，當網路上未有預先建構好的繞徑拓樸時，每個節點的轉送服務重要性指標也可被用在連接到固定網路節點的選徑上。當每個節點的最大轉送數目有限制時，利用轉送服務重要性指標來選擇路徑所產生的成功建立連線機率會比一般常用的最短路徑選徑策略高。

Multi-hop cellular networks that integrate the characteristics of both cellular and mobile ad hoc networks have received increasing attention. Providing incentives to foster cooperation among nodes is an important prerequisite for the success of the multi-hop cellular networks. Most works on the incentive approaches for enabling forwarding packets just employ fixed-rate pricing. The purpose of this research is to present appropriate incentive pricing schemes for relaying services considering both relaying costs and service availability. First, this study proposes a pricing scheme that dynamically adjusts the price of the feedback incentives based on the number of mobile nodes to maximize the revenue of the network provider while maintaining service availability. Then, in order to consider the individual impact of each mobile node on supporting hop-by-hop connections, we introduce the concept of location-based incentive pricing for relaying services. The proposed pricing scheme shifts incentives from the nodes of low importance to the nodes of high importance so that it increases service availability without additional costs. Finally, the Quality-of-Relay (QoR) value of each mobile node is adopted to select a relaying path for connecting to the central base station. Simulation results indicate that the proposed QoR-based routing scheme causes a lower new call blocking probability than the shortest-path routing scheme under a certain constraint on maximum relaying capacity of each mobile node.