Upgrading Cellular Mobile Networks
0 likes429 views
This document discusses optimization strategies for cellular mobile networks, focusing on enhancing backhaul performance through the integration of packet-based aggregation and cellular backhaul switching technology. Key improvements include reducing backhaul requirements from 12 E1s to 4 E1s, enabling dynamic resource allocation, and ensuring quality of service monitoring without interference with customer services. The approach allows operators to expand their customer base and introduce new 3G and 4G services more effectively while preserving existing network investments.
Upgrading Cellular Mobile Networks
- 1. Unified Backhaul Performance Optimization Upgrading Cellular Mobile Networks Dr. Stanislav Milanovic PhD in Computer Science and Engineering
- 2. Abstract This presentation highlights the upgrading steps for improved traffic aggregation at the regional hub sites in order to optimize traffic backhauling to the network core. In addition, a reliable, passive access solution to cellular mobile traffic for a Quality of Service (QoS) monitoring and billing has been proposed.
- 3. The evolution of 3G radio technologies have dramatically increased bandwidth delivery to the end user and at the same time shifted the bandwidth bottleneck from the radio segment to the cellular backhaul network. To minimize both, Capital Expenditure (CapEx) and Operating Expenditure (OpEx) of the cellular backhaul, mobile operators have been seeking a unified backhaul solution that is technology-agnostic and addresses cellular backhaul evolution phases while maximizing the reuse of the existing backhaul infrastructure (Figure 1). Introduction
- 4. Figure 1. Cellular mobile backhaul network showing last and second-mile connection and an optical SDH ring connection to the RNC and BSC.
- 5. Objective A converged backhaul has been envisioned by employing cellular backhaul switching technology for economically managing backhaul network expenses during 3G evolution while reusing the actual backhaul infrastructure. Cellular backhaul switching is a sub-class of multi-service switching (MSS), designed to address cellular backhaul evolution needs. The following step was to provide the QoS management tool and billing system access to the cellular mobile traffic in a reliable, transparent and cost-effective manner.
- 6. Packet-based Aggregation In order to deliver both 2G and 3G services, the operator decided to deploy a packet-based aggregation solution based on ATM MSS that reduced transmission expenses and opened up bottlenecks in the microwave links (Figure 2). ATM switches were deployed over a bundle of E1s (IMA group). On the input side there are 6 E1 lines to carry 2G GSM traffic from 8 base stations. Another 6 E1s carry 3G UMTS traffic from 6 base stations. The 6 GSM E1s are groomed and a circuit emulation service is used to concentrate the traffic such that 4.5 E1s will suffice. The 6 UMTS lines are concentrated into 2.5 E1s. As a result, 7 E1s are required to connect the hub site to the core network, which is a significant reduction from the original 12.
- 7. Figure 2. ATM MSS implementation
- 8. This solution, which is based on a standard ATM multi-service switching enables the mixing of all traffic on one IMA group with static partitioning between GSM and UMTS. However, standard ATM MSS architecture is limited by the fact that the output comprises dedicated GSM and UMTS channels. These are entirely separate networks that cannot be shared using a dynamic allocation process.
- 9. Backhaul Optimization The need to further improve network performance while cutting down network expenses led to an alternative solution able to deliver much higher network performance by adding the application-layer cellular backhaul switches. This eliminated idling and protocol inefficiencies by adaptation of the actual information to Variable Bit Rate traffic flows. It performed statistical multiplexing of all 2G and 3G traffic, obtaining maximal statistical gain for maximum network efficiency, and provided full flexibility for sharing network resources according to actual 2G and 3G traffic demands (Figure 3).
- 10. Figure 3. Optimized Backhaul The E1 lines have been further reduced to four from the initial 12. In addition, the network is entirely and dynamically shared between GSM and UMTS traffic.
- 11. Project Outcomes The integration of cellular backhaul switching improved network performance by maximizing network efficiency, providing full network flexibility, and enabling real-time network resource allocation based on support of QoS for multi-generational voice, video, and data traffic. The operator has the flexibility now to expand his customer base as well as to introduce new 3G/4G services for his customers at his own pace, while preserving his investment in the network.
- 12. QoS and Billing Access for Cellular Mobile Services Critical issues to the success of cellular mobile services: 1. Maintaining a high level of QoS, and 2. accurately tracking and billing service usage. Since wireless technologies move most of the traffic to IP, an IP network monitoring access has been proposed for integration within the core network infrastructure. The best place in the switching infrastructure to tap the wireless traffic would be at the links between the SGSN and the GGSN, because it was the first place that traffic from all mobile devices had been converted to IP (Figure 4).
- 13. Figure 4. Cellular mobile infrastructure with data monitoring switch for monitoring access Deployed monitoring solution in the core network cleanely isolated the QoS monitoring tool and billing system from the service traffic, ensuring that they would never interfere with the customer's service.
- 14. Conclusion Implemented cellular backhaul switching has cut backhaul requirements by a factor of three (from 12 E1s to 4 E1s) and has also dynamically optimized the resources dedicated to 2G and 3G services. The operator could expand his customer base as well as to effectively introduce new 3G and 4G services for his customers. Integrated monitoring access layer gave the monitoring tool layer, which included the QoS and billing equipment, full visibility of the cellular mobile traffic without any risk of it being negatively impacted. It substantially reduced the complexity and risk of routing the traffic to the QoS monitoring tool and billing system because it did not rely on configuring switch Span ports that would otherwise be necessary. It was cost-effective because monitoring tap ports were much less expensive than switch Span ports.