As the popularity of wireless communication increases rapidly, the unlicensed Industrial Scientific and Medical (ISM) band becomes crowded. Interference avoidance thus becomes an important issue when designing wireless communication in the unlicensed ISM band. As shown in related works, channel hopping with blacklisting is a promising mechanism addressing interference in 802.15.4e time slotted channel hopping (TSCH) networks. However, the blacklisting mechanism changes the number of channels used, and thus requiring the frequency hopping sequence (FHS) be regenerated. A time-random channel selection mechanism avoids regeneration overhead; however, it breaks close-to-optimality property of the default FHSs, which in turns leads to high probability of interference. In this paper, we propose a new algorithm that generates FHSs in presence of interference without regeneration overhead, and at the same time maintains the optimality property. With the new proposed mechanism, we can generate FHSs with one designed original sequence. Analysis and simulation results show that optimal/near optimal properties are achieved by these new FHSs.
