## 2 Related Studies
An FEC is a channel coding technique that adds redundancy to transmitted data to achieve error control [28] by which the transmitter sends data along with the redundant information and the receiver distinguishes and identifies only the original data and requires the redundant bits only in the case of some bit error or data loss. Unlike Automatic Repeat Request (ARQ), when an error is detected within the transmitted data, FEC restores it without requesting re-transmission. Thus, when transmission delay matters, FEC may be a quicker and more suitable option to choose [9]. In FEC, redundant bits are added to the original bitstream by the FEC encoder [29]. Hamming codes, Reed-Solomon (RS) codes, Hadamard codes, BCH codes, Expander Codes, Golay codes, and Reed-Muller codes are various common methods for adding redundancies to data [30]. The receiver checks sent data, performs error detection, followed by error correction according to the type of code, and accepts data only if they match the specification. The authors [31] analyzed several FEC approaches for error-free transmission of videos in varying network scenarios. RS encoding is applied at the packet, frame, and sub-Group-of-Pictures (GoP) level by considering various attributes of the videos. The decision tree algorithm is used to apply RS codes to the encoding parameters of videos to maintain the required QoE. However, applying FEC at the packet level increases the network overhead due to the redundancy added to each packet. The authors [32] suggested a systematic content-dependent FEC technique which uses RS codes on H.264/AVC encoded frames. Although the results exhibit smoother video quality and higher performance gain, the scheme increased the complexity of the FEC encoding method. Recently, Nunome [33] presented a joint model of Application Layer FEC (AL-FEC) and an error-concealment technique for H.264/AVC video to assess the subjective QoE and objective QoS of videos transmitted over a noisy channel. This method adopted RS coding and concluded that the efficiency of the code rate is not only dependent on the condition of the transmission channels but also on the contents. Then, in [34], an adaptive source FEC coding scheme was proposed for the mitigation of end-to-end distortion during real-time video messages, and both consecutive and sporadic video frame drops were minimized. In [35], an Exclusive OR (XOR)-based Publicly Verifiable Secret Sharing (PVSS) scheme called GRGPVSS was proposed. An FEC coding scheme dubbed PATON was presented to address issues affecting the effective delivery of high-definition mobile videos such as high transmission rate, limited bandwidth, transmission errors, and throughput fluctuations [36]. The researchers [37] applied an FEC strategy by considering Un-Equal Protection (UEP). The proposed method achieved the same performance as that obtained from the expanding window strategy but with an improved computational cost. A coded caching scheme was proposed based on Combinatorial Structures [38]. These structures are called resolvable designs and can be applied in a natural pattern. The scheme was implementable for a wide range of parameters. Then, in [39], researchers applied FEC and Opportunistic Routing (OR) and improved the QoS. They also achieved a lower Symbol Error Rate (SER). Furthermore, the proposed strategy (QFEC-OR) was more effective in respect to 20 to 80 QoS perception parameters. In [40], the researchers proposed an FEC algorithm based on the lookup table architecture of distance Bit Error Rate (BER) at the Medium Access Control (MAC) layer of wireless networks. Furthermore, the authors of [41] proposed an error correction and detection technique for noisy images to provide error-free transmission by adding parity bits to the bitstream before transmission. To assess the impact of error control schemes, the authors of [42] studied the performance of various quality metrics of error-concealed images and videos using multiple error concealment techniques.