Independent Service Sharing Coordinator Mechanism Design for Multi-Operator LTE Small Cell and Spectrum Sharing Market

With the tremendous growth in wireless data traffic and services, mobile network operators (MNOs) may need to deploy large amount of network infrastructure to meet the unprecedented capacity and data rate demand, which increases capital expenditures (CAPEX) and operating expenses (OPEX) correspondingly. The development of radio access network sharing (RAN sharing) and wireless network virtualization (WNV) brings the possibility of small cell sharing. Each MNO can reduce large amount of de-ploying cost and gain profits by cooperation. In this thesis, we define multi-operator LTE small cell sharing market (MoSCS) as multiple operators share their LTE small cells and spectrum resources. In this market, the MNO plays two roles simultaneously: Providing Operator(PO) and Accessing Operator(AO). As a PO, MNO sells small cell resources to its own subscribers and other AOs. To satisfied its own subscriber’s de-mand, the MNO plays as an AO, seek for resources from other POs. However, the MNOs are competitors to each other, which brings small cell sharing market many problems. Especially, the MNO may not want to share their resource and information to the competitors. A fair and independent third-party coordinator, supervised by government, is a success model in the public service competition. Therefore, in this thesis, we propose a novel coordination framework called independent service sharing coordination (ISSC). The basic design problems include: Q1. How to design a ISSC framework to facilitate the MNO to share its small cell and spectrum resources without revealing MNO’s information? Q2. Under the ISSC framework, how to design the small cell resource allocation mechanism based on the demand requirement of different MNOs? Q3. Under the ISSC framework, how to determine a reasonable access price to enhance the profit of each MNO by sharing resources? Based on the above problems, we proposed a novel ISSC framework and the cor-responding mechanism design for MoSCS market in this thesis. (1) Designed a novel coordination framework: This framework is a novel idea, which consists of resource estimation, resource allocation, price determination and subscriber estimation. ISSC platform ensures the security of the information provided by MNOs. Then, ISSC calculates the equilibrium of price and resource demand to create a win-win situation for MNOs. (2) Designed an iterative ISSC mechanism with competitive pricing and coopera-tive resource allocation: The ISSC mechanism design combines Bertrand game and Bankruptcy by consid-ering two roles of MNO: PO and AO. (2.1) ISSC use Bertrand game to model the equilibrium of competitive price of PO to the corresponding demand of AO In an area, each PO compete with each other, which is a monopoly market. In this thesis, we first model the demand restriction as soft restriction. Then, by using the competitive pricing to estimate the demand requirement of each AO. Therefore, we formulate this problem into Bertrand game and find Nash equilibrium price and the corresponding demand of AO. Solving the Nash problem by ISSC can reduce large amount of information transmission and negotiate time. (2.2) When the demand of AOs is large than a PO’s small cell can supply, ISSC allo-cates the resources based on resource restriction and the contribution of demand re-quirement of an AO by using Bankruptcy game In this thesis, we formulate the allocation problem into Bankruptcy game when the PO’s small cell resources can not satisfy the demand of AOs. Moreover, we use Shapley value to allocate PO’s resources to AO in the ISSC platform, which is an algo-rithm allocates resources based on the contribution to the shortage of resources. (2.3) ISSC use subscriber to find the price and demand requirement iteratively ISSC estimate the quality of each MNO by the difference between AO’s demand and the resource allocation result by using Shapley. Then, by using a Poisson-based subscriber transition model to estimate subscriber number iteratively, we can further analyze the effect of subscriber number to the demand, price and total payoff. In this thesis, we verify and analyze our mechanism by designing several scenari-os based on different subscriber density of MNO in the MoSCS market. The simulation results show that the total subscriber number, price and resource allocation of small cell will converge in our proposed scenarios. Because in our subscriber estimation model, if the MNO’s quality is poor, its will lose its subscribers in a Poisson distribu-tion. Meanwhile, its competitors’ subscriber will increase. As a MNO’s subscriber de-crease, the remain subscriber can get more resource. Therefore, the quality of the MNO increase. In other words, the MNO’s quality will decrease as its subscribers increase. When the quality between MNO become balance, the system will tend to stable. By comparing the results of total payoff and the subscriber number, if the small cells resources are enough (Low density scenario), the utilization of base station can raise up to nearly 100%. Each MNO’s total payoff increase to 3~6 times and do not compete other MNO’s subscribers, which is a win-win situation. When the small cells can not provide enough resources to AOs (High density scenario), each MNO still gain profit. However, the MNO with poor quality will keep losing of its subscribers not until its quality is raised. Though MNO lose its subscribers, but through the estimated results of AO to the demand of POs from ISSC platform, MNO can evaluate whether to deploy new small cells. The deployment may satisfy the requirements of subscribers and im-prove the quality, which will avoid the subscriber to leave. We implement an online ISSC platform for LTE small cell sharing market by us-ing AppServ and Python. AppServ includes Apache, PHP and MySQL, which allows window system to run solution stack called Windows-Apache-MySQL-PHP(WAMP) and manage MySQL database through phpMyAdmin. We use python scripts to run our algorithm and update the results to the ISSC platform.