This paper proposes new scheduling algorithms for best effort (BE) traffic classification in business femtocell networks. The purpose of traffic classification is to provide differentiated services to BE users depending on their traffic classes, and the concept of traffic classification is called Inter User Best Effort (IUBE) in CDMA2000 1x Evolution Data Optimized (EVDO) standard. Traffic differentiation is achieved by introducing Grade of Service (GoS) as a quality of service (QoS) parameter into the scheduler's decision metric (DM). New scheduling algorithms are called QoS Round Robin (QoS-RR), QoS Proportionally Fair (QoS-PF), QoS maximum data rate control (DRC) (QoS-maxDRC), QoS average DRC (QoS-aveDRC), QoS exponent DRC (QoS-expDRC), QoS maxDRC-PF (QoS-maxDRC-PF). Two different femtocell throughput experiments are performed using real femtocell devices in order to collect real DRC values. The first experiment examines 4, 8, 12 and 16 IUBE users, while second experiment examines 4 IUBE + 2 Voice over IP (VoIP), 8 IUBE + 2 VoIP, 12 IUBE + 2 VoIP, 16 IUBE + 2 (VoIP) users. Average sector throughput, IUBE traffic differentiation, VoIP delay bound error values are investigated to compare the performance of the proposed scheduling algorithms. In conclusion, QoS-maxDRC-PF scheduler is proposed for business femtocell environment.

In this letter, we propose a distributed channel assignment where each basestation selects a set of channels shared by multiple users through time domain scheduling for best effort services. The proposed scheme distributedly assigns the channels considering a cochannel interference from neighboring basestations and its own traffic load condition. The computer simulation demonstrates that the proposed scheme appropriately assigns the channels to the basestations taking into account these requirements.

The proportional delay differentiation (PDD) model provides consistent packet delay differentiation between classes of service. Currently, the present schedulers performing the PDD model cannot achieve desired delay proportion observed in short timescales under light/moderate load. Thus, we propose a Non-Work-Conserving (NWC) scheduler, which utilizes the pseudo-waiting time for an empty queue and forces each class to compare its priority with those of all other classes. Simulation results reveal that NWC outperforms all current schedulers in achieving the PDD model. However, NWC suspends the server from transmitting packets immediately if an empty class has the maximum priority, resulting in an idle server. Therefore, we further propose two approaches, which will serve a best-effort class during this idle time. Compared with other schedulers, the proposed approaches can provide more predictable and controllable delay proportion, accompanied with satisfactory throughput and average queuing delay.

This paper describes the implementation of an optical switch control system for best-effort multi-wavelength path assignment in DWDM networks based on the SLAMNet (Statistical Lambda Multiplexing Network) that provides dynamic path assignment capabilities without signaling between nodes. The platform of the prototype system consists of a hardware and operation system that are commercially available in the market. We developed the control functions of the SLAMNet as application software to run on the platform. The control function monitors the instantaneous bit rate of the traffic in the wavelength paths and autonomously sets up or releases optical channels in an independent and distributed manner. We demonstrate that the prototype system achieves a switching time of less than 28 milliseconds, which can respond to the burst traffic that emerges and disappears within a fraction of a second in backbone networks. This result indicates that the network architecture SLAMNet is applicable for best-effort multi-wavelength path assignment as an overlay network built on a legacy infrastructure that has no signaling capabilities. The design description and detail hardware configuration are presented. The control mechanisms and performance analysis are also included.

The problems caused by misbehaving flows are becoming important issues in high-speed best effort networks. In this paper, we propose the MXQ (MaXimal Queuing) mechanism which correctly identifies and adequately penalizes misbehaving flows. Identification and penalization are the keys to controlling misbehaving flows, which is believed to be crucial for providing best effort services to a large number of residential customers at reasonable cost. The proposed mechanism consists of estimating incoming traffic at network edges and selective packet discard at network nodes. This combination realizes the identification and penalization in a correct, adequate and easy to understand way, thus maintaining the stability and efficiency of best effort networks. A number of experiments are performed on a prototype system to examine the unfairness caused by different TCP implementations, which is one type of misbehavior. The results show that the MXQ mechanism can adequately penalize the misbehaving flows, and can improve fairness, even when differently implemented TCP flows are present.

In this paper an ATM call level model, where service classes with QoS guarantees (CBR/VBR) as well as elastic (best effort) services (ABR/UBR) coexist, is proposed and a number of simulations have been carried out on three different network topologies. Elastic traffic gives on the network level rise to new challenging problems since for a given elastic connection the bottleneck link determines the available bandwidth and thereby put constraints on bandwidth at other links. Thereby bandwidth allocation at call arrivals but also bandwidth reallocation at call departure becomes, together with routing, an important issue for investigation. Two series of simulations have been carried out where three different routing schemes have been evaluated together with two bandwidth allocation algorithms. The results indicate that the choice of routing algorithm is load dependent and in a large range the shortest path algorithm properly adopted to the mixed CBR/ABR environment performs very well.