Beyond Communications: Can ISAC Provide a Rationale for 6G?
暫譯: 超越通訊：ISAC 能否為 6G 提供正當性？

We currently have separate communication systems and sensing, or radar-like, systems. The concept of bringing these two systems together using 6G's integrated sensing and communications (ISAC) feature is alluring. Not only would there be cost savings from less infrastructure and lower energy consumption, but the dense grid of cellular base stations might enable sensing in areas not previously possible. The additional revenue from new use cases might help fund the deployment costs for 6G and revitalize the finances of the mobile operators.

From a technical and standardization perspective the signs are positive. The frequencies and bandwidths proposed for 6G, at 6GHz and above, provide sufficient resolution for many sensing applications, research has demonstrated viable sensing, for example of drones, and there is a strong standardization roadmap already underway in 3GPP. With the ITU designating ISAC as one of the pillars of 6G, the concept has much legitimacy.

However, success is far from assured. The economics of ISAC appear weak. ISAC might require most base stations to be modified, a denser grid of new base stations deployed, and might increase energy and computing costs. The revenue streams currently appear relatively small compared to communications revenues and without government support, perhaps using ISAC as part of a drone and missile defense system, the business case does not appear to work. There are also serious privacy concerns about a system that can monitor individuals, potentially even down to some of their vital signs, that may need fundamental legal decisions and if handled badly could result in vigilante action against networks.
This book clearly sets out the case for and against ISAC and draws clear conclusions as to what will be needed if it is to be successful.

The book is structured as follows:

• The first three chapters are introductory, covering the concept of ISAC, its history and the national and regional initiatives that are in place.
• The next three chapters are more technical, covering existing sensing solutions, the possible architectures for ISAC and the waveforms being considered.
• Chapters seven and eight look at the spectrum that 6G ISAC might use and the 3GPP standardization activities underway and predicted.
• Chapter 9 considers how data can be "fused" together from multiple sensors to improve the sensing performance.
• Chapter 10 looks at ISAC's vulnerabilities, for example to jamming and spoofing, and how these vulnerabilities can be reduced or eliminated while Chapter 11 considers future research directions.
• Chapters 12 to 13 look at the use case for commercial and military sensing and develop simple estimates for the revenues that might accrue for each case.
• Chapter 14 considers the overall business case for ISAC and Chapter 15 looks at whether the MNOs will struggle with a new concept.
• Chapters 16 and 17 examine the privacy issues associated with widespread sensing and the consumer backlash that might occur if handled badly.
• Chapter 18 concludes by discussing the future of ISAC.