Intelligent reflecting surfaces (IRSs) were introduced in the literature in order to enhance the performance of the wireless systems. However, from a cellular service provider's point of view, a concern with the use of an IRS is its effect on out-of-band (OOB) quality of service. Specifically, if there are two operators, say X and Y, providing services in a given geographical area using non-overlapping frequency bands, and if operator X uses an IRS to optimally enhance the throughput of it's users, does the IRS degrade the performance of operator Y? We study this scenario by analyzing the ergodic sum-rates achieved by both the operators under round-robin scheduling. We also derive the complementary cumulative distribution function of the change in the effective channel gain at an OOB user with and without the IRS, which provides deeper insights into the effect of the IRS on the overall channel quality. Surprisingly, we find that even though the IRS is randomly configured from operator Y's point of view, the OOB operator still benefits from the presence of the IRS, witnessing a performance enhancement for free. This happens because the IRS introduces additional paths between the transmitter and receiver, increasing the overall signal power arriving at the receiver and providing diversity benefits. We verify our findings via numerical simulations, and conclude that an IRS is always beneficial to every operator, even when the IRS is deployed to optimally serve only one operator in the system.

翻译：文献中引入了智能反射表面(IRS),目的是提高无线系统的性能。然而,从蜂窝服务提供商的角度来看,对使用IRS的担忧是其对带外(OOB)服务质量的影响。具体地说,如果有两个操作者,例如X和Y,使用非重叠频率波段在特定地理区域提供服务,并且如果操作者X使用IRS来最佳地提高用户的吞吐量,IRS是否降低操作者Y的性能?我们通过分析双轮机器人列表操作者所实现的ERgodic总和率来研究这一假设。我们还从有效频道获得的改变在OOB用户和不使用IRS的情况下产生的互补累积分布功能,后者更深入地了解IRS对整个频道质量的影响。令人惊讶的是,即使IRS只是从操作者Y的视角随机地配置,OOB操作者仍然受益于IRS系统的存在,同时通过IRS提供不断增强的信号,并且通过不断提高的接收者之间的整个接收器,从而可以免费实现对改进。</s>