Auction-Based Coopetition between LTE Unlicensed and Wi-Fi

Abstract

Abstract-Motivated by the recent efforts in extending LTE to the unlicensed spectrum, we propose a novel spectrum sharing framework for the coopetition (i.e., cooperation and competition) between LTE and Wi-Fi in the unlicensed band. Basically, the LTE network can choose to work in one of the two modes: in the competition mode, it randomly accesses an unlicensed channel, and interferes with the Wi-Fi access point using the same channel; in the cooperation mode, it delivers traffic for the Wi-Fi users in exchange for the exclusive access of the corresponding channel. Because the LTE network works in an interference-free manner in the cooperation mode, it can achieve a much larger data rate than that in the competition mode, which allows it to effectively serve both its own users and the Wi-Fi users. We design a second-price reverse auction mechanism, which enables the LTE provider and the Wi-Fi access point owners (APOs) to effectively negotiate the operation mode. Specifically, the LTE provider is the auctioneer (buyer), and the APOs are the bidders (sellers) who compete to sell their channel access opportunities to the LTE provider. In Stage I of the auction, the LTE provider announces a reserve rate, which is the maximum data rate that it is willing to allocate to the APOs in the cooperation mode. In Stage II of the auction, the APOs submit their bids, which indicate the data rates that they would like the LTE provider to offer in the cooperation mode. We show that the auction involves allocative externalities, i.e., the cooperation between the LTE provider and one APO benefits other APOs who are not directly involved in this cooperation. As a result, a particular APO's willingness to cooperate is affected by its belief about other APOs' willingness to cooperate. This makes our analysis much more challenging than that of the conventional second-price auction, where bidding truthfully is a weakly dominant strategy. We show that the APOs have a unique form of the equilibrium bidding strategies in Stage II, based on which we analyze the LTE provider's optimal reserve rate in Stage I. Numerical results show that our framework improves the payoffs of both the LTE provider and the APOs comparing with a benchmark scheme. In particular, our framework increases the LTE provider's payoff by 70% on average when the LTE provider has a large throughput and a small data rate discounting factor. Moreover, our framework leads to a close-to-optimal social welfare under a large LTE throughput.Index Terms-Coexistence of LTE and Wi-Fi in unlicensed band, auction with allocative externalities, symmetric Bayesian Nash equilibrium.

Coexistence of Cellular and IEEE 802.11 Technologies in Unlicensed Spectrum Bands -A Survey

“…However, instead of either competition or cooperation, a combination of both types of games is used in several works such as [117]. In [117], a novel spectrum sharing framework that considers both cooperation and competition, (also termed as coopetition) between LTE and WiFi in the unlicensed band is proposed. The LTE network can select one of the two modes, either competition mode or cooperation mode.…”

“…Cooperation is especially important under certain conditions, including if the data rates of both LTE and WiFi are reduced considerably due to co-channel interference, it would be beneficial for both LTE and WiFi to cooperate with each other. Hence, to sum up, the basic idea here is that both LTE and WiFi should explore the possible benefits of cooperation before deciding whether to enter a competition [117].…”

Traffic Offloading in Unlicensed Spectrum for 5G Cellular Network: A Two-Layer Game Approach

“…Some coexistence mechanisms for LAA and WiFi have been studied in [ 7 , 8 , 9 , 10 , 11 , 12 ], which show that LTE and WiFi could coexist in a friendly manner, and improve the performance of the whole network. There are, at this stage, three main LTE mechanisms under considerations for ensuring fair coexistence with WiFi, namely, Listen Before Talk (LBT) [ 7 , 8 ], Carrier Sensing and Adaptive Transmission (CSAT) [ 9 , 10 , 11 , 12 , 13 , 14 ] and traffic offloading [ 15 , 16 , 17 , 18 , 19 ]. In the LBT mechanism, a transmitter would listen to the medium and determine whether it could transmit [ 6 , 7 ], which is similar to the incumbent Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) mechanism in IEEE 802.11 [ 5 ].…”

“…Game theory has an important position in wireless resource management and there are also some game theory applications in LAA field [ 17 , 18 , 19 , 23 ]. In [ 17 ], a spectrum sharing scheme based on the decision tree was built through the channel condition, load condition, etc., and then parts of data were offloaded from the operator which asked for a favor to the operator with few stations based on a repeated game.…”

“…However, LTE and WiFi operators belong to different communication protocols and it is not practical to predict the state of the other operator and use the dynamic game with complete information in fact. A second-price reverse auction game was built in [ 18 ]: LAA network choses to work in a competition mode or in a cooperation mode according to their announced reserve rate. If they work in a competition mode, LAA randomly accesses the unlicensed channel and competes with WiFi based on a typical coexistence mechanism such as CSAT or LBT.…”