This paper addresses the challenge of Quality-of-Service (QoS) routing in ad hoc networks, where communication is wireless and direct between adjacent nodes, necessitating multiple hops for distant nodes. The authors propose a distributed QoS routing scheme that selects paths with sufficient resources to meet delay or bandwidth requirements in a dynamic, multihop mobile environment. The proposed algorithms handle imprecise state information and use multipath parallel routing to increase the likelihood of finding a feasible path. They also consider both QoS requirements and cost optimality to improve overall network performance. Fault-tolerance techniques are employed to maintain routing paths when nodes move, join, or leave the network. Extensive simulations demonstrate high call-admission ratios and low-cost paths with modest routing overhead, even under high information imprecision. The algorithms are designed to support soft QoS, allowing for transient periods of QoS disruption but ensuring it when established paths remain unbroken.This paper addresses the challenge of Quality-of-Service (QoS) routing in ad hoc networks, where communication is wireless and direct between adjacent nodes, necessitating multiple hops for distant nodes. The authors propose a distributed QoS routing scheme that selects paths with sufficient resources to meet delay or bandwidth requirements in a dynamic, multihop mobile environment. The proposed algorithms handle imprecise state information and use multipath parallel routing to increase the likelihood of finding a feasible path. They also consider both QoS requirements and cost optimality to improve overall network performance. Fault-tolerance techniques are employed to maintain routing paths when nodes move, join, or leave the network. Extensive simulations demonstrate high call-admission ratios and low-cost paths with modest routing overhead, even under high information imprecision. The algorithms are designed to support soft QoS, allowing for transient periods of QoS disruption but ensuring it when established paths remain unbroken.