I. Introduction
Wireless networks reliability, severely affected by temporal multipath fading, can be improved through cooperative communication using relays. Past many research, such as [1]–[3] and references therein, have worked on dual hop cooperative systems. Relaying over multiple hops in addition with cooperation has come up with the solution of temporary extension of a network without substantial establishment of infrastructure or bringing the dead-spots into the network coverage of a cellular system [4]–[14]. Multihop relay networks can be divided into two categories, one with relaying layers/stages having a single relay [6]–[9], and the other with multiple relays in each relaying layer [11]–[14]. In this paper the network is divided into arbitrary parallel relaying paths, each path with arbitrary number of relays. We analyze the outage probability of this system using selective decode and forward (DF) relays [2] in Nakagami- fading. In contrast to amplify and forward (AF) relaying, DF protocol blocks the propagation of noise at the expense of complex circuitry.