Device-to-Device Communication in 5G Cellular Networks
‘Device-to-device communication in 5G cellular networks: Challenges, solutions, and future directions’ is one of the research papers found in the Institute of Electrical and Electronics Engineers (IEEE) communications magazine. IEEE published the article in the year 2014. Three authors engineered this document, namely: Mohsen Nader Tehrani, Murat Uysal, and Halim Yanikomeoglu. All communications from one device to another, as defined in a licensed cellular bandwidth, have to go through a base station (BS). However, machines also have a terminal relay system that can as well transmit signals. With this kind of advancement in wireless communication come several challenges. Apart from the rise in technology, this paper will inform the reader concerning crucial problems and recommendations for improvements in the future.
The number of smart handheld devices is rapidly increasing throughout the globe. When the population grows, the demand for mobile devices as well shoots to higher levels. These users tend to use applications that will need more than the fourth-generation (4G) networks. Next-generation applications that involve massive media such as video streaming, multimedia file sharing, will need more robust connectivity. Cooperative communications will give a chance for these users to enjoy the next generation (5G) connections.
Cooperative communications will bring forth some developments that had not existed previously. One of the advancements is whereby network nodes will help each other to relay information. Device users will then have the chance to enjoy advantages such as reliable links, efficient spectrums, high system capacities, and a more extensive range of transmissions. Cooperative communications have been studied widely in the literature, as well as fixed terminal relaying. Fixed terminal relaying involves the use of BS to promote interaction between devices, at the same time utilizing low power. However, the 4G Long Term Evolution (LTE)-Advanced standard has already been using fixed terminal relaying.
Fixed terminal relaying is suitable, but device conveying will be an advancement. Device relaying involves the use of a cell phone, tablet, laptop, or any portable device that is wireless and has cellular connectivity, as transmission relays for each other. This concept is supported by device-to-device (D2D) functionality, which dictates that two devices in close range can communicate in the licensed cellular bandwidth with a BS or with minimal BS utilization. In as much as fixed terminal relaying has improved mobile systems, the implementation of device relaying will now bring out the full potential that has not been there before.
There is a change in attitude towards D2D communication functionality. Operators have not been offering enough consideration that the D2D feature requires. All first four generations of cellular networks have majorly related D2D as a tool for reducing costs in local service provision. The wireless market, however, is experiencing changes that were never there before. For instance, there is an increasing number of services and applications which will operate after they have located the neighboring device. Considering this kind of advancement, the cost of communication reduces.
Devices that are close to one another can use D2D can share resources effectively. It becomes easier for a person to share spectrum, computational power, applications, and even social contents in the social media world we are living in now. Service providers can decide to reduce the usage of local area networks in large stadiums and malls where many devices are close to one another. Moreover, a natural calamity like an earthquake might destroy all the infrastructure. The scenarios above are sufficient evidence that D2D communication technology is a necessity in the world currently. Thus, for any service provider considering to hold a place in the market, D2D is the best way to go.
Data security is a challenge imposed by current D2D trends. Applications like Wi-Fi and Bluetooth improvise D2D communication functionality. The problem is that D2D does not guarantee the safety of the information that is on transfer. The reason why there is no data security is that the band in use is not licensed. Also, the quality of service (QoS) provided by these applications is not assured. Since cellular networks can offer both security of information and high QoS, market vendors are thinking about introducing D2D to mobile systems.
D2D functionality requires the security of the user’s information. The next available device relays the user data, and this tampers with the privacy of the user. A possible way to guarantee security is that when taking part in the device tier, users need to have closed access. Closed access dictates that unless a device appears among the trusted ones, then it cannot take part in D2D with the device in the topic. This list can consist of say neighbors living in a particular area or colleagues at work. For those devices not mentioned on the list, they will have to communicate through the macrocell tier.
Open access, however, possesses a significant challenge when it comes to D2D communication functionality. In this type of access, devices can act as relays to any other device without defining any terms of access. There is no monitoring of tools that use D2D services in open access types. When there are no restrictions in place, it means that the information transferred is openly vulnerable to threats and attacks. Therefore, closed access will enable higher levels of information security compared to open access.
The ability to manage interfaces in D2D is also a concern. In both devices relaying with operator controlled link establishment (DR-OC) and direct D2D communication with operator controlled link establishment (DC-OC), the BS is the one that allocates resources and also sets up calls. The BS uses centralized strategies that help to manage interfaces. However, device relaying with device controlled link establishment (DR-DC) and direct D2D communication with device controlled linked establishment (DC-DC) do not have a centralized means that helps to supervise the resource allocation between machines. Using the same license-band threatens the performance of macrocell users. Also, there is an interference that exists when operating under the device tier. The solution to such a problem is to design a two-tier network that has multiple strategies of interference management tagged with appropriate schemes of resource allocation. Other ways include pooling of resources, bargaining game, control of admission, distribution of power, cluster partitioning, and lastly, relay selection.
In DC-OC, the BS acts as one of the communicating parties. When the BS performs multiple operations, then macrocell users have a limited opportunity of maintaining security. One of the ways to reduce interference of BS functioning is to authenticate the devices that perform relays. With this kind of measure, the device user can maintain high levels of data security. Another way to ensure minimal interference is through managing the allocation of spectrum. When the technology allows for such kinds of renovations, then there can be sufficient data security as well as QoS in the performance of devices.
Recommendations
Another critical issue concerning the D2D communication functionality of devices is pricing techniques. Operators and device vendors should improvise a customer-friendly way in which the prices of the modern D2D devices will attract a lot of customers. Some of the customers perhaps would prefer that they continue to use the old technologies if they find that this new one is not friendly for their pockets. Thus, the merchants have to answer the question of what price to put forward for D2D technology so that customers do not feel overcharged.
Many factors influence the pricing of D2D technology. One of the issues is that for any device acting as a relay, it must use many components like battery, data storage capacity, and also bandwidth. Therefore, manufacturers need to consider these factors for them to arrive at the most favorable pricing schemes. The operator can also create a secure D2D connection, which allows for the trading of resources amongst the users. Therefore, the devices should also expect to pay for security and QoS.
Conclusion
Wireless communication in recent times has seen an increase in the number of users demanding services. However, the 4G network connectivity is already under pressure, and therefore operators need to advance. D2D communication functionality is one of the significant improvements in wireless technology. D2D enables the transfer of large volumes of data between devices where one of the tools acts as a BS. However, the problem arises when it comes to pricing issues. As much as the vendors are trying to implement D2D technology, they have to make sure that consumers are not overpriced on these services.