With the growing demand for mobile data, cellular service operatorsare increasingly turning to small cells — picocells, microcells, metrocells and femtocells — to dealwith the capacity crunch in dense urban areas and to add coveragein areas with low or zero cellular signal levels, such as indoorsand in remote rural locations. But the capacity of small cells, which use licensed spectrum, isdependent on the availability of that limited spectrum, can bedegraded by interference between small cells, and requiressignificant planning. To cope, some service providers are lookingto use Wi-Fi to augment their investment in small cells. BACKGROUND: 3G, 4G, Wi-Fi coming together in small cells for mobile data A number of vendors, including BelAir Networks (acquired byEricsson), Ruckus Wireless and IP.Access, have announced Wi-Fi integrated LTE and HSPApicocells.
At Mobile World Congress 2012 , a number of announcements concerned Wi-Fi integrated small cell technology. Alcatel-Lucent,for example, announced a secure Wi-Fi gateway for small cells andan integrated Wi-Fi option for its existing femtocell and picocellproducts. Cisco also rolled out a small cell gateway to help operators integrate Wi-Fi into small cells, while AirspanNetworks announced the integration of carrier Wi-Fi to its LTEsmall cell solution. Integrating the Wi-Fi radio in a small cell will open a host ofopportunities and benefits to cellular carriers, including: * Cost-effective additional capacity: Integrating Wi-Fi radios intosmall cells provides cost-effective capacity and additionalcoverage for small cells, particularly for those cells that aretargeted for public usage, like picocells, over and above theiravailable cellular capacity. This additional boost will furtherhelp small cells deliver seamless data services in dense urbansites reeling under the capacity crunch, and will also enable asmall cell site to gracefully handle peak capacity hours.
* Service extension to non-cellular devices: Since Wi-Fi supporthas become ubiquitous on everything from laptops to tablets andcameras, integrating Wi-Fi into small cells will allow carriers toextend data services to non-cellular devices, adding an additionalsource of revenue. * Smart and intelligent data offload schemes: With Wi-Fiintegration, smart data offload schemes will enable serviceproviders to selectively allow voice and other carrier-managedvalue added services to be served through the carrier’s corenetwork (via cellular connection), while offloading Internettraffic to Wi-Fi. These offload schemes can provide mobile usersthe best of both worlds, cellular connectivity for voice and valueadded carrier services, and Wi-Fi connectivity for cost-effectivedata services. This would also enable carriers to launchcost-effective plans. T5 LED Tube Light
[Also see: ” Wi-Fi’s promise for cell carriers running out of options “] * Wi-Fi on-load: Wi-Fi, when part of a small cell, can be easilylinked to the core network over the same backhaul link, allowingcarriers to provide end-to-end quality of service guarantees andcellular-like security for Wi-Fi traffic. This essentially means that all carrierservices, including the voice, value added and data services can beeffectively and efficiently provisioned on the Wi-Fi radio itself.In fact, carriers will be able to roll out Wi-Fi only,cost-effective plans featuring full-fledged access to all sorts ofcarrier services — talking, surfing, messaging, etc. The conceptof Wi-Fi on-load is being aggressively targeted by serviceproviders, such as Republic Wireless. * Seamless cellular Wi-Fi handovers: Integration of cellular andWi-Fi radios in a small cell also allows for seamless handover oftraffic from cellular to Wi-Fi radio and vice versa as requirementsshift due to, say, excessive interference, battery drain oroverload conditions on either the cellular or Wi-Fi radio. Seamlesshandovers assures the continuity and quality of traffic for amobile user regardless of radio access technology. China LED Flat Panel Lights
* Local breakout: This function essentially allows users to connecttheir mobile devices to the local home, office, or campus networkwithout traversing the operator’s core or any other outsidenetwork. Local breakout capability can be easily achieved with asmall cell that has integrated Wi-Fi. * Benefits of Wi-Fi radio virtualization: Wi-Fi radios can bevirtualized into multiple exclusive Wi-Fi networks, leading to manybenefits. That makes it possible, for example, to multiplex Wi-Fioffload and Wi-Fi on-load functions together over the same physicalWi-Fi radio. Similarly, other services such as business promotionsand advertising can be easily multiplexed over a virtualized Wi-Firadio along with regular services. Led Fluorescent Tube Lights
Such multiplexing allows moreflexibility for the carrier to cash in on various differentiatedservices over the same small cell site without extra capex/opex.Virtualization also helps carriers to share/resale part of Wi-Ficapacity cleanly. * Wi-Fi backhaul: The presence of a Wi-Fi radio in a small cellalso makes it possible for carriers to use Wi-Fi as an effectivewireless backhaul link for cellular traffic when wired options arescarce. Moreover, Wi-Fi radios in multiple small cells can bearranged in a mesh for high availability and reliable backhaul.[Also see: ” LTE performance will hinge on picocell backhaul “] * Newer business models: With integrated Wi-Fi, a small cell can beleveraged into newer business models, such as managed/ hosted Wi-Fi services for venues, enterprises, etc., which is not possible withthe cellular-only capability of small cells. Moreover, thesebusiness models will allow carriers to further leverage theirlicensed spectrum via the cellular radio of the cell.
Built-inWi-Fi also presents the unique opportunity of selling/sharing thewhole or partial Wi-Fi capacity (via virtualized Wi-Fi radio) tothird parties, such as hotspot aggregators, MVNOs, etc. * Low cost of ownership: Without Wi-Fi integration, carriers needto separately plan and spend for capex and opex to pursue bothsmall cell and Wi-Fi strategies, which can result in a considerablyhigher cost of combined ownership. However, with integration at thesite, carriers can reap the benefits of both strategies quickly andwith lower cost of ownership, as integration allows sharing ofresources between the two, saving on extra site rental andadditional equipment, backhaul and other costs. Carriers can alsosave on separate OAM, gateway or provisioning modules, required forboth strategies via integration, which otherwise might be requiredin a non-integrated scenario. While in the past traditional small cell and Wi-Fi technology wereconsidered competitors, it is now understood the technologies cancomplement each other well.
Co-existence of both technologies in asingle box at a particular site will ensure the use of the righttechnology at all locations and at all times, providing a seamlessmobile experience that is completely agnostic to the type of radioaccess technology used. Gupta is presently working as team lead at Wesley CloverCommunications Solutions. He has been in the field of Wi-Fi accessand security for more than seven years and is a frequentcontributor to leading magazines and blogs on wireless topics. Read more about anti-malware in Network World’s Anti-malware section.