Concatenated hybrid ARQ - a flexible scheme for wireless real-time communication

The concept of deadline dependent coding (DDC) has previously been suggested by the authors for maximizing the probability of delivering the required information before a given deadline in a wireless communication system.. In this paper, these principles are further developed using concatenated codes with iterative decoding, providing a new level of flexibility and robustness for DDC protocols. The strategy of DDC is to combine different coding and decoding methods with automatic repeat request (ARQ) techniques in order to fulfill the application requirements within a wireless realtime communication system. These requirements are formulated as two quality of service (QoS) parameters: deadline (t_DL) and probability of correct delivery before the deadline (P_d), leading to a probabilistic view of realtime communication. An application can negotiate these QoS parameters with the DDC protocol, thus creating a flexible and fault-tolerant scheme.