以拍賣促成異質次級網路分享接取具差異頻道

Abstract

為了減輕對無線通信的爆炸式和多樣化的需求，通過認知無線電等新技術在異構次級網絡（HSN）之間共享未充分利用的頻譜被認為是一種有效的方法。 載波聚合技術的發展使得頻譜共享更有前途，因為來自各個頻帶的具差異頻道可以被聚合，以提供更高的資料流通量和數據速率。例如，LTE-WLAN聚合（LWA）是聚合LTE頻帶和非授權頻帶以最佳利用頻譜的新興技術之一。由於相關通信技術的發展，HSN可以共享具有不同傳播特性的頻道。 頻譜共享中最關鍵的問題之一是HSN之間的干擾控制。由於不兼容的MAC / PHY層，實現空中控制並不容易。HSN對帶寬和傳輸範圍的多樣化要求使這個問題進一步複雜化。針對上述問題，Zhan等人於2015年，考慮了一個頻譜提供商的問題，頻譜可用於租用HSN。他們採用集中式的拍賣框架，通過網絡管理層的市場機制設計，協調HSN之間的頻譜次級共享和共存問題。他們提出的基於Vickrey-Clarke-Groves（VCG）拍賣設計具有高度表現力的招標格式，具有有效的區域劃分，允許HSN規定對帶寬和傳輸範圍的各種需求，並實現真實標性質，個人理性和預算平衡的理想屬性。然而，他們的研究中假設頻道是同質的，忽略了HSN對具差異頻道的各種估值，這能導致頻道分配不佳。HSN對頻道組合的估值也被忽視，失去了更好的頻道分配和更高收入的機會。 為了解決具差異頻道和頻道組合的影響，本論文考慮了一個共存網絡，其涉及一個頻譜提供商（SP）將未使用的具差異頻道共享到多個HSN。建立在Zhan設計之上，具體設計挑戰如下：（C1）為了解決HSN的不同估值，如何定義投標靈活性以及SP設置底標的空間？ （C2）設計機制能否在不犧牲頻譜利用的情況下實現良好的經濟性質，包括真實標性質，個人理性和預算平衡？ 為了解決上述挑戰，本文提出了一種以具差異頻道考慮為基礎的單邊VCG拍賣（UVAH / DC），具有三種新穎的設計： 1. 全面的招標格式，允許HSN靈活指定經營地區，期望的頻道和組合以及出價; 2. 組合底標使SP能夠靈活地設置底標以捕獲市場偏好; 3. 建立於組合底標，最大虛擬出價創建了高於SP底標的虛擬出價，確保獲勝付款不低於相應的底標，以避免收入不足。 我們證明UVAH / DC實現了HSN的真實標性質。如果任何兩個不相交組合具有底標，且聯合組合的的底標未指定或不低於不相交組合底標的總和，也可以實現個人理性和預算平衡。對一個情境下900個實例的數值實驗表明，與Zhan的設計相比，UVAH / DC在平均頻譜收入和頻譜出租比（ROR）分別提高了36.4％和9.4％。UVAH / DC不僅為SP提供了更大的激勵來租賃未充分利用的頻譜，而且提高了整個頻譜利用率。

To mitigate the explosive and diversified demands for wireless communications, shared access of underutilized spectrum among heterogeneous secondary networks (HSNs) via new technologies such as cognitive radio has been deemed as an effective approach. The development of carrier aggregation technology makes spectrum sharing more promising because differentiated channels from various bands can be aggregated to provide higher throughput and data rate. For instance, LTE-WLAN aggregation (LWA) is one of the emerging technology which aggregates LTE-band and unlicensed band(s) to make good use of spectrum. Owing to the growth of relevant communication technology, it becomes possible for HSNs to share channels form various bands which have different characteristics. One of the most critical issues in spectrum sharing is interference control between HSNs. Due to the incompatible MAC/PHY layers, it is not easy to achieve over-the-air control. This issue is further complicated by HSNs’ diverse requirements on bandwidth and transmission range. In view of above issues, Zhan et al., 2015, considers the problem of a single provider with spectrum bands available for rent to HSNs. They adopt a centralized auction-based framework to coordinate the secondary spectrum sharing and coexistence problem among HSNs through a market mechanism design at network management layer. Their proposed Vickrey-Clarke-Groves (VCG) auction-based design has a highly expressive bidding format with effective region partition that allows HSNs to specify various demands for bandwidth and transmission range and achieves the desirable properties of truthfulness, individual rationality and budget balance. However, channels are assumed to be homogeneous in their work, ignoring HSNs’ various valuations toward differentiated channels which may lead to bad channel allocation. HSNs’ valuations toward channel combinations are also neglected, losing the opportunity for better allocation and higher revenue. This thesis considers a coexistence network that involves one spectrum provider (SP) sharing unused differentiated channels in a target area to multiple HSNs and addresses the effects of differentiated channels and channel combination. Built on top of Zhan et al’s design, specific design challenges are as follows: (C1) How to define the bidding flexibility for HSNs as well as the reserve pricing space for SP to include HSNs’ diverse valuations of channels and combinations? (C2) Assure that an new auction design maintains the good economic properties of truthfulness, individual rationality and budget balance. To address these challenges, this thesis proposes an Unilateral VCG-based Auction for HSNs with Differentiated Channels consideration (UVAH/DC) with three novel designs: 1. Fully expressive bidding format that allows HSNs to flexibly specify operating regions, desired channels and combinations and bid offers; 2. Reserve prices by SP over packages that give SP the flexibility of setting bundle reserve prices to capture market preferences; and 3. Maximum virtual bid generation that creates virtual bids from SP’s reserve prices over bundles which guarantee winning payment is no less than the corresponding reserve price to avoid revenue deficiency. We prove that UVAH/DC achieves the economic property of truthfulness of HSNs. Individual rationality and budget balance can also be achieved if for any two disjoint packages with reserve price specifications, the reserve price of joint package is either not specified or no less than the sum of disjoint packages’ reserve prices. Numerical experimentation over a scenario with 900 instances shows that, compared to Zhan et al’s design, UVAH/DC improves, in average spectrum revenue and spectrum rent-out ratio (ROR) by 36.4% and 9.4% respectively. That is, UVAH/DC not only provides stronger incentive for SP to lease underutilized spectrum, but also increases the whole spectrum utilization.