Implementation of Extra Efficient Bandwidth Utilization Dynamic Bandwidth Allocation Algorithm to support Differentiated service classes in XGPON

Dynamic Bandwidth Allocation (DBA) algorithm is necessary for the efficient utilization of bandwidth in XG-PON. Most of the existing DBA algorithms have not utilized the unused bandwidth of a queue with other service classes queue. The Efficient Bandwidth Utilization (EBU) uses a Borrow Refund (BR) method in the update operation to use the unused bandwidth between a traffic class queue of which has some flaws in the BR method. The EBU mechanism causes a reduction in the allocation of bandwidth and increases the delay for the next traffic class. This paper presents an Extra Efficient Bandwidth Utilization (EEBU) algorithm, which overcomes the limitations mentioned above with proper polling and scheduling mechanism. The theoretical and simulation results show that EEBU improvements for T-CONT 2 delay are 1% and 10%, and for T-CONT 3 delay are 8% and 22%, and for T-CONT 4 delay by 6% and 4.5% compared to the EBU and Giga PON access network (GIANT) respectively.

Performance evaluation of comprehensive bandwidth utilization for 10-gigabit passive optical network

Bandwidth allocation during upstream transmission is crucial to determine the efficiency and performance of a XG-PON. For XG-PON, bandwidth assignment is done based on T-CONT which represents a traffic class as per ITU recommendation. DBA scheme used in this paper is based on CBU to assign bandwidth to ONUs based on the T-CONT supporting QoS as per SLA. In this paper, CATV traffic is used as traffic generator which used for generation of Ethernet frames and results showed expected trend of mean upstream delay for traffic class T2, T3 and T4 as compared to recommended value which is below 1.5ms. These results prove that CBU can also be implemented on real time traffic.

Comprehensive Polling and Scheduling Mechanism for Long Reach Gigabit Passive Optical Network

Dynamic bandwidth assignment (DBA) schemes for long reach PONs face a suffer from higher upstream channel idle time due to long round trip time (RTT). In ITU PONs, the DBA schemes; Immediate allocation with colorless grant (IACG), Efficient bandwidth utilization (EBU) and GPON redundancy eraser algorithm (GREAL) minimize idle time by sending bandwidth grants to the optical network units (ONUs) every downstream frame (DF). EBU further improves IACG by utilizing unused bandwidth (UBW) of other traffic classes. Sending the grant results every DF requires optical line terminal (OLT) to remember all previous grants sent to ONU during RTT and subtract them from the received queue reports. Since, both IACG and EBU assign the excess bandwidth equally to ONUs. Therefore, the OLT is actually not aware of the complete grant to each traffic class and thus do not subtract these completely from receiving reports. This leads to wastage of bandwidth and higher US delays due to over granting. GREAL resolves this problem by not utilizing the excess bandwidth which also leads to increased US delays. The proposed scheme in this study eliminates this shortcoming by allocating excess bandwidth to each traffic class completely at the OLT. Moreover, the UBW assignment mechanism of EBU is also improved. Simulation results show a 50–85 % reduction in delays of type-2 (T2) and type-3 (T3) traffic classes versus GREAL and IACG and up to 40 % reduction in delays for type-4 (T4) versus EBU.

Traffic Class Prioritization-Based Slotted-CSMA/CA for IEEE 802.15.4 MAC in Intra-WBANs

This paper proposes an improved Traffic Class Prioritization based Carrier Sense Multiple Access/Collision Avoidance (TCP-CSMA/CA) scheme for prioritized channel access to heterogenous-natured Bio-Medical Sensor Nodes (BMSNs) for IEEE 802.15.4 Medium Access Control (MAC) in intra-Wireless Body Area Networks (WBANs). The main advantage of the scheme is to provide prioritized channel access to heterogeneous-natured BMSNs of different traffic classes with reduced packet delivery delay, packet loss, and energy consumption, and improved throughput and packet delivery ratio (PDR). The prioritized channel access is achieved by assigning a distinct, minimized and prioritized backoff period range to each traffic class in every backoff during contention. In TCP-CSMA/CA, the BMSNs are distributed among four traffic classes based on the existing patient’s data classification. The Backoff Exponent (BE) starts from 1 to remove the repetition of the backoff period range in the third, fourth, and fifth backoffs. Five moderately designed backoff period ranges are proposed to assign a distinct, minimized, and prioritized backoff period range to each traffic class in every backoff during contention. A comprehensive verification using NS-2 was carried out to determine the performance of the TCP-CSMA/CA in terms of packet delivery delay, throughput, PDR, packet loss ratio (PLR) and energy consumption. The results prove that the proposed TCP-CSMA/CA scheme performs better than the IEEE 802.15.4 based PLA-MAC, eMC-MAC, and PG-MAC as it achieves a 47% decrease in the packet delivery delay and a 63% increase in the PDR.

Network Selection Solution For Heterogeneous Wireless Environment

The future generation of wireless network consists of heterogeneous wireless networks that provide uninterrupted services to user when roaming through different access networks. This future generation of wireless network will provide increase in data rate, decrease in end to end latency, energy efficient network environment etc. This is possible due to different enabling technologies i.e. Device to Device Communication, Spectrum Sharing, Enhancement of Quality of Experience in the selection process, Energy Harvest Network and Multi-Radio Access Technologies Association. The selection of network that supports these technologies for different traffic class is done using different decision making techniques. In this work, decision making techniques like Multi Attribute Decision Making algorithms and Game Theory Model (Bankruptcy and Evolutionary Game Model) are used for selection of network in a environment composed of Universal Mobile Telecommunication System, Wireless Local Area Network and Wireless Interoperability for Microwave Access. The different network attributes (available bandwidth, packet delay, packet jitter, packet loss and cost per byte) are taken into consideration for analysis. The analysis is done for conversational, streaming and background traffic class. Also, preference to network attribute`s is introduced using Analytical Hierarchy Process and Standard Deviation Method. The network selection results using Multi Attribute Decision Making algorithm and Game Theory Model are compared and it is found that Game Theory based selection involves learning process therefore consider more than one maximum weighted network attribute for selection whereas MADM algorithm depends on maximum weighted attribute. Further, different decision making techniques are compared on the basis of Relative Standard Deviation. The accuracy of algorithm can be calculated on the basis of difference between ranking values of alternatives.

Heuristic Algorithm Based Traffic Classified Routing Algorithm in Distributed Satellite Cluster Network

The architecture of distributed satellite cluster network (DSCN) is presented and the characteristics of DSCN topology change are illustrated. On the basis of analyzing the acquisition method of network status and route calculation, we proposed a heuristic algorithm Ant Colony Optimization (ACO) based traffic classified routing (ATCR) algorithm for DSCN. Simulation results shows that, ATCR algorithm can balance network traffic effectively, and the end-to-end delay of every traffic class is less than TCD algorithm. The end-to-end delay of traffic class A and class B is less than ACO algorithm which does not use traffic classification. ATCR has a better performance on packet delivery ratio than ACO and TCD because ATCR reduces the number of heavy load link as well as packet loss caused by congestion.