Massive MIMO is considered one of the key enabling technologies for 5G networks
As wireless communication systems must meet more and more data transmission demands, the inadequacy of the protocols used to ensure that data is transmitted to the correct user can leave the system vulnerable to attack. A recent paper by Berk Akgun of the University of Arizona and colleagues in IEEE TransacTIons on InformaTIon Forensics and Security explores this type of attack. They found that in some cases, the transfer rate of data could drop by more than 50 percent when using Massive Multiple-Input Multiple-Output (MIMO) technology. Massive MIMO is considered one of the key enabling technologies for 5G networks. MIMO is an established technology in wireless communications whereby two or more transmitters and receivers transmit and receive data simultaneously. But as base stations transition to massive MIMO, base stations will be equipped with more and more antennas to transmit signals that are more likely to interfere with each other. To solve this problem, smaller periodic signals called pilots are assigned to and sent from each user, which ensures that the data is delivered to the right person. A major limitation of this approach is the limited number of pilots available. This limitation becomes especially acute as the number of communication channels per base station continues to grow. Sometimes, multiple users must be assigned the same pilot sequence, which interferes with proper data transmission and results in poor system performance. This is called pilot pollution. However, attackers can also exploit this pollution to intentionally interfere with data transmission. "An attacker can generate the exact same pilot sequences as legitimate users' pilot sequences and send those sequences along with those users to distort the base station's channel estimates," Akgun explained. This strategy ultimately reduces users' data transmissions rate. In this paper, Akgun and collaborators explore pilot contamination strategies that attackers can use under different conditions. Their results show that when an attacker is very close to the base station (within a distance of 300 meters or less), he or she is enough to use its own pilots to reduce the overall transmission rate of a massive MIMO system by more than 50%. Unfortunately, their results also show that attackers can slow data rates even further away from the base station. Attacks can also become more severe if the attacker knows the location of certain users. "The attacker has a limited power budget to contaminate the pilot transmissions of legitimate users," Akgun explained. In this way, attackers can increase the impact of their attacks on overall system performance.†If the attacker's pilot signal is strong enough to threaten the privacy of wireless communications, pilot contamination can also be used to take away the transmitted data. The researchers looked at how far this strategy could be maximized under different conditions, and found that the closer the attacker was to the base station, the significantly more vulnerable the data transmission was. In conclusion, this paper highlights the vulnerability of massive MIMO systems and the need for new protocols for securing the communication channels established through these systems. Engine Parts Belt,Water Pump Belt,fan belt,dynamo belt Chongqing LDJM Engine Parts Center , http://www.ckcummins.com