## 4 The Performance Parameters and Application Scenarios of 6G Networks
### Technical Requirements
There are plans to enhance this metric further, aiming for a tenfold improvement to reach 10\({}^{7}\) devices per km\({}^{2}\) in the future [25]. 6. **Network energy efficiency:** Ensuring energy efficiency is crucial for cost-effective mobile networks and minimizing carbon emissions in the realm of green communication. This aspect plays a critical role in societal and economic considerations. Despite the significant improvement in energy efficiency per bit compared to previous generations, the early deployment of 5G networks has faced criticism for its high overall energy consumption. In the upcoming 6G networks, the goal is to increase KPI performance 10 to 100 times than 5G. The goal is to reduce the power consumption in communication while improving energy efficiency per bit [25]. 7. **Spectrum efficiency:** This is an important KPI for measuring improvements in radio communication systems. The standard for peak bandwidth efficiency in 5G is set at 30 bits per second per hertz (bps/Hz) in the downlink and 15 bps/Hz in the upload. For example, using real-world data to guide the development of new 6G radio technologies could lead to three times better frequency efficiency than the 5G infrastructure [25]. 8. **Area traffic capacity:** This is a metric for assessing a network's aggregate mobile traffic capacity within a defined area, considering elements such as available bandwidth, spectrum efficiency, and network densification. In 5G, the baseline criterion for area traffic capacity is established at 10 megabits per second per square meter (Mbps/(m\({}^{2}\))). There are expectations that in certain deployment scenarios, such as indoor hotspots, this capacity could reach up to 1 gigabit per second per square meter (Gbps/(m\({}^{2}\)) [25]. Besides the above eight key requirements, to properly evaluate 6G networks, a few additional key metrics are discussed below. 9. **Delay jitter:** This refers to the variability in the time it takes for packets to reach their destination, leading to fluctuations in transmission delay. In 5G systems, the delay jitter is typically around 1 ms [26], whereas in 6G systems, it has been reduced to as low as 1 \(\mu\)s, achieving an improvement of 1000 times. 10. **Reliability:** This denotes the capacity to transmit a specified volume of traffic within a predetermined time frame with a high probability of success, particularly crucial in URLLC scenarios. In 5G networks, reliability is measured by a success probability spanning from 1 to 10\({}^{-5}\) when sending a 32-byte data packet within 1 ms, factoring in the channel quality at the coverage edge in an urban macro environment deployment scenario. Expectations for the next-generation system include a significant improvement of at least two orders of magnitude, reaching a success probability of 1\(-\)10\({}^{-7}\) or 99.99% [25]. 11. **Positioning:** This metric, offered by the 5G positioning service, surpasses 10 m. There is a rising demand for increased precision in positioning, especially in diverse vertical and industrial applications, notably in indoor environments where satellite-based positioning systems may lack adequate coverage. The integration of THz radio stations, renowned for their capability in high-precision positioning, is projected to elevate the accuracy supported by 6G networks to the centimeter level [25]. 12. **Coverage:** In the context of 5G technology, coverage refers to the integrity of radio signal reception within a single base station's service area. The scope of this service area is gauged by the coupling loss metric, which accounts for the aggregate long-term channel loss between a terminal and a base station, factoring in elements like antenna gains, the attenuation of signal strength over distance, and shadowing from obstacles. As we transition to 6G networks, the concept of coverage is anticipated to expand considerably.