Fixed vs Mobile IRS Placements

The Intelligent Reflecting Surface (IRS) is an enabling technology for beyond 5G and 6G. IRSs are passive reflective surfaces that can modify signals in a controlled manner. They are utilized to enhance coverage and spectrum with high energy efficiency and, therefore, are referred to as passive relays. This energy efficiency makes them a promising technology. The reflective nature of these surfaces allows for a line-of-sight path through the IRS between a transmitter and receiver when the direct path is obstructed with low-energy consumption. However, this requires careful positioning. Proper IRS positioning is crucial for optimizing network performance. Most studies consider a fixed placement of the IRS, but the IRS can also be mobile to better adapt to the dynamics of certain networks. In this paper, we propose to compare the fixed and mobile placements of several IRSs. The problem is modeled using an IRS activation strategy for each period, employing different comparison criteria.