Networks are growing faster every day, reaching formidable levels of complexity and traffic volume and making the task of managing them prodigiously. But the networking has seen developments, from 2G to 3G, to 4G. The new era will see 5G with faster and modern networking throughout the world.
5G will connect about 7 trillion wireless devices or things, shrink the average service creation time from 90 hours to 90 minutes, and enable advanced user controlled privacy. By connecting all aspects of life, 5G aims at a digital society that requires high service availability and security using a diverse set of technologies. 5G aims to vary the globe by connecting something to something.
Current network technologies face two main obstacles. Firstly, there is a need for the integration of new generation mobile and wireless access systems with legacy networks that support deployed investment, such as LTE, 3G, 2G, WiFi, satellite, etc. This integration is optimized for brand new kinds of services, such as self-driver services and Industry.
Secondly, the increasingly large amounts of data being managed by the network make smart network management necessary. In relation to these difficulties, several high-level challenges emerge, such as:
- the accommodation of new stakeholders, such as data owners, vertical sectors, public administration, smart cities, communities of people, charities and SMEs
- new requirements in terms of energy efficiency
- network threat detection and reparation
- the design of virtualized network infrastructure
- the management of large amounts of generated data
the definition of and compliance with new evaluation metrics and their target values, such as increased throughput, decreased latency, better energy efficiency, reduced service creation time, increased battery lifetime and better coverage.
In order to cope with these emerging requirements, a new generation of networks is required. This new generation, which will be embodied in what is known as 5G, is based on a new set of societal and technological challenges to be driven by a joint effort between trade, academia, and public funding agencies.
This new 5G generation is based on a new set of societal and technological challenges to be driven by a joint effort between industry, academia and public funding agencies.
Interference management in heterogeneous networks: because of the dense preparation of heterogeneous nodes in 5G networks, one approach of improving the resource utilization to use the available resources as a spectrum underlay manner. However, for the underlay communication 5G networks, interference management is one of the key challenges.
One of the biggest challenges for multi-tier heterogeneous networks is to mitigate inter-cell and inter/intra tier interference. In addition to non uniformity and dense preparation of wireless devices, coverage and traffic load imbalance due to varying transmit powers of different BSs make the interference management and resource allocation issues more difficult than those in standard single-tier systems.
However, the 5G network also comes with security and privacy challenges to the users:
- The ultra-dense environment results in more interference sources. For example, in crowded subway trains, lots of terminals exist; therefore, signals may have more reflecting and scattering paths. The interference model becomes more complex.
- The traditional parameters to measure and evaluate the impact of interference, such as interference temperature and interference threshold, may not expose the overall interference measure and performance control of the networks. More suitable parameters should be discussed to give a better indication between interference managing results and throughput, associated with energy efficiency and other system-level parameters.
- For a whole and honest assessment of 5G wireless systems, more performance metrics should be considered. These embrace spectral potency, energy efficiency, delay, reliability, the fairness of users, QoS, implementation complexity, and so on. Thus, a general framework ought to be developed to gauge the performance of 5G wireless systems, taking into account as many performance metrics as possible from different perspectives.
- Realistic channel models with proper accuracy-complexity trade-off are indispensable for some typical 5G scenarios, such as massive MIMO channels and high-mobility channels (e.g., high-speed train channels and vehicle-to-vehicle channels).
- Conventional MIMO channel models cannot be directly applied to large MIMO channels within which totally different|completely different} antennas could observe different sets of clusters. Massive MIMO channel models should take into account specific characteristics that make them different from those in conventional MIMO channels, such as the spherical wavefront assumption and non-stationary properties.
- A major issue in interference-tolerant CR networks in 5G is how to reliably and practically manage the mutual interference of CR and primary systems. Regulating the transmit power is crucial for the metal system to be with different authorized systems. An interference temperature model is introduced for this purpose to characterize the interference from the CR to the licensed networks.