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4G network offload: Radio access network and mobile backhaul solutions

Wireless operators looking at 4G network offload to cope with growing mobile traffic have two options for relief – radio access network (RAN) offload using mobile hotspots and femtocells, and mobile backhaul solutions to move wireless traffic to the metro network fast.

One of the most profound challenges of broadband services for network operators is the growing disconnect between traffic growth and revenue growth.

WiFi appears to be the favored strategy currently because retail tablets and laptops/netbooks come with a WiFi interface.

Tom Nolle, President, CIMI Corp.

For mobile operators, it threatens to destabilize new service planning by reducing the return on wireless infrastructure investment

Usage-based pricing may offer some relief, but it may be a difficult remedy to apply in a competitive market, and regulatory intervention may limit or even prevent it in some areas.

4G wireless network services offer higher bandwidth per-user than earlier generations and could result in even more traffic, so operators are eager to find ways to reduce the cost of handling that traffic without impacting their competitive position. The answer may be getting wireless traffic off expensive wireless networks quickly using 4G network offload.

Offloading 4G network traffic focuses on two areas—the radio access network (RAN) and Mobile backhaul.

  • The goal in the RAN is to find alternative connection strategies for appliances with high data use, especially tablets and laptop dongles, that could congest cells and degrade service to other customers.
  • The goal of mobile backhaul network offload is to quickly transfer Internet traffic to the wireline Internet, getting it off of any premium backhaul paths that require a higher investment per bit because they are architected to support premium services. (Hairpinning -- routing traffic in and out of 4G backhaul networks to support roaming users -- should be avoided for low-revenue data handling.)

4G RAN offload options: Look to mobile hotspots and femtocells

4G radio network offload is available either by deploying WiFi hotspots or through the use of femtocells. The guiding principle of femtocell or WiFi offload is to place hot spots in areas where network use is higher than normal, such as hospitality locations. Many operators already provide WiFi services commercially in such hotspot zones, so using WiFi as a 4G network offload strategy may not increase infrastructure costs at all.

WiFi appears to be the favored strategy because retail tablets and laptops/netbooks come with a WiFi interface. Providing the user with a “mobile hotspot” that bridges between an operator’s 4G service and WiFi, makes the 4G conduit available to any local WiFi device, so pure WiFi devices can still use 4G services indirectly.

Femtocells are essentially very small local cells that use the operator’s own cellular frequency and are managed similarly to traditional 4G cells. These offer the operator greater control over the service, but they require either a 4G interface on the device or a mobile hotspot (sometimes called MiFi)..

But WiFi and femtocells are both network offload strategies for the RAN, so hotspot traffic will still have to be carried as mobile backhaul traffic in the metro network, and that may create additional offload issues.

Continued: Mobile backhaul offload strategies and their effect on Evolved Packet Core design.

This was last published in February 2011

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