HomeMobile EuropeInterview - Active solutions for in-building Wireless

    Interview – Active solutions for in-building Wireless


    Mobile Europe:
    Can you tell us a little more about Zinwave to start with? Where it has come from and the market it operates in?

    Luma Musa:
    Zinwave is a UK company based in Cambridge, VC funded since 2005 after being spun out of a joint research project between the Universities of Cambridge and London. That research developed a way of transmitting Radio Frequency (RF) over multimode optical fibre, and Zinwave has now built on that to become a pioneer of a unique new active Distributed Antenna Systems (DAS) solution for in-building wireless coverage.We launched our product, the Zinwave 3000, this year and are currently shipping to customers.

    The in-building coverage market is going through a strong period of growth currently. In Europe up to now, in-building coverage has not necessarily been a huge topic, mainly because 2G coverage has generally been very good. But the advent of 3G has changed that. Obviously, 3G uses higher frequencies, meaning building penetration of the radio worsens. Although 3G has not really taken off yet in a mass way, usage is definitely starting to rise – and with this has come an increasing reliance on mobile data services and applications.

    Added to this, users, especially corporate and enterprise users are becoming more and more demanding, expecting ubiquitous coverage for their wireless services and needs. This means that in-building coverage has, in a number of areas, rapidly risen up operators’ list of priorities.

    Mobile Europe:
    What emerging wireless services and applications for corporates are driving this?

    Luma Musa:
    In terms of corporate demands, there is of course mobile voice, but also mobile data – especially email. The growth of PDA and Blackberry usage is driving the demand for better wireless coverage inside buildings. The corporate user is going to want the seamless continuation of coverage indoors (whether in his office building or a public building.  And we have the advent of mobile broadband (whether WiMAX or HSPA)of course.

    Also, in-building coverage for emergency services is becoming essential. In the US many cities and counties are enacting ordinances that require a certain level of wireless coverage for Public Safety services inside commercial buildings of a certain size, to ensure that police and the emergency services can communicate with their wireless devices inside those buildings.

    Additionally, we are seeing real estate developers and property owners think in terms of adding value to their project by designing in indoor cellular coverage, so that large buildings, campuses and projects are built with the ability to provide coverage to their tenants.

    Mobile Europe:
    So what technologies are best suited to meet this increasing demand?

    Luma Musa:
    The traditional method available when an operator was faced with the need to boost indoor coverage, whether it be for filling in gaps in coverage or adding more capacity, was to add micro-cellular coverage  – essentially to throw more carriers at the problem. But with 3G that is just not cost efficient. And it’s also not efficient technically because in a CDMA environment, you have different cell characteristics, such as cell breathing, meaning that you can’t just add more coverage to an area without affecting other cells.

    Pico-cells too have offered a solution, and they can often be the correct one. But the effective niche for pico-cells is for the smaller building and the SME. And with both these single technology approaches you will be tasked to provide coverage across all the likely service bandwidths, from 800MHz or 900MHz upwards.

    Passive DAS has also been quite a successful solution, but the drawback there is that the RF signal does not travel very far over RF cable. You suffer significant signal loss with distance, and also with higher frequencies. It’s also, by its very nature, not manageable, being composed of Passive components.

    This is why Active DAS with RF distribution over fibre cabling is now widely  becoming the favoured method of providing in-building coverage. Active DAS is fed from a repeater or a base station (BTS), and the signal is then distributed inside the building over fibre cable with remote units and antennas converting the optical signal back to wireless, and transmitting the signals at the locations they are needed. Active DAS systems have the advantage over traditional Passive solutions in large buildings and spaces where such systems encounter length limitations.

    ABI Research says that the technology will have the most significant positive impact on in-building wireless coverage over the next five years. In its figures it forecasts that the revenues from the sale of Active DAS will have overtaken Passive DAS by 2009, with an estimated 19,000 Active DAS deployments taking place in the year, generating nearly $2.5 billion in sales. That’s quite large growth from $1.5 billion revenues in 2007. ABI also puts the sweetspot for Active DAS in buildings with a footprint of between 100k and 500k square feet.

    Mobile Europe:
    So what are the advantages of Zinwave’s approach to Active DAS?

    Luma Musa:
    Although there are other systems on the market, the advantages of Zinwave’s Active DAS system are many.

    First, and uniquely, it is wideband; meaning you can deploy it to carry multiple services, independent of frequency using the same common hardware equipment. And the system is not just wideband over the fibre, but end-to-end, from the base station or repeater to the remote unit. In that sense it is service independent – being able to support any number or combination of services, protocols or frequencies. This also means that an operator, corporate or building owner can have peace of mind knowing that they have future protection if they need to add more services later.
    Other competitive products on the market deploy service-specific radio units at the end of the fibre cable to provide the radio coverage. This means if you want to add more services, then you need to add units at the remote end, increasing cost and management complexity.

    Traditionally, carrying wideband radio signal over multimode fibre would generate a “fluffy” signal, with reflectivity and other factors degrading performance, so that you couldn’t carry very high frequencies. Other solutions have been to carry the signal in low frequency and convert it up again.
    Our solution, the Zinwave 3000, allows businesses and facilities to deploy a single centrally-managed platform to support multi-service/multi-operator wireless coverage. Any number or combination of services are supported – including 2G/3G to LTE; WiFi; WiMAX; TETRA; private mobile radio; RFID; DVB-H; etc – enabling simultaneous mobility for employees, consumers and emergency services. It is also the only active DAS system that can support Time Division Duplex (TDD) services.

    Additionally, we support a very low cost of installation and deployment. It is a very simple architecture of primary and secondary hubs connected to remote units distributed around the building where coverage is needed. Our system is a true wideband system – so no parallel service specific units and no cabling overlays are required, keeping equipment and installation costs lower. This scalability and flexibility also ensures wireless coverage can be delivered to the most complex of locations and structures, including multi-building campus sites, high-rise offices, or large complexes such as airports. The Zinwave 3000 can utilise single-mode or multi-mode fibre (with a coaxial option), allowing the use of existing fibre infrastructure where available.

    Mobile Europe:
    What kind of environments require this multi-service approach?

    Luma Musa:
    A multiservice, multi-operator solution is often required, especially in multi-tenanted buildings where the DAS has to be able to simply and cost effectively provide this requirement. It’s about addressing the end customer need but also guarding the operator’s investment by having a solution that can grow, expand, and change with changing standards such as a move to 3G or LTE, and cope with frequency migrations.

    Other vertical markets include any large buildings, public or private such as shopping malls and airports, hospitals, universities and campuses, industrial facilities and building owners for multi-tenanted enterprise buildings.

    A multiservice wideband approach is really about offering service flexibility, as well as the ability to meet all a building’s users’ demands, whether that is for cellular voice, or provision of high bandwidth application to a notebook or PDA.

    Mobile Europe:
    So what challenges do you face getting these products to market, in terms of the possible concerns and demands of your customers?

    Luma Musa:
    I think there are different challenges in different areas. For operators, clearly meeting their approvals and certification processes is very important. And we are about to go into many operators’ labs to get approval. If you are going to take a feed from a donor BTS, the frequencies and carriers your service uses clearly mustn’t interfere with the operators’ outdoor network.

    But, perhaps more of an issue for us is addressing operators’ concerns around the control of their networks. In-building coverage offers an opportunity for the business model to shift a bit. It’s possible a corporate, or building owner, or a wholesaler, would own the system themselves, or in some way share the cost of build-out with the operator. But this also means the operator should not need to worry too much about not being in control of all aspects of mobile coverage.

    For vendors and system integrators it’s about simplicity and cost effectiveness so that systems can be designed and installed quickly and with minimum disruption. They also require flexibility; to support various multiple services, and legacy and emerging technologies and frequencies, and to cover various areas with varying service requirements. You have to remember different wireless services/applications or mobile operators’ services may be required on different floors or different parts of a building. Solutions also need to be able to accommodate new and emerging applications, to be future proof.
    For corporates, there are questions such as: If not all your employees have a corporate phone, and you need a multi-operator system to support coverage – so who pays? If the corporate pays: decide on the right infrastructure, and think about protecting your investment with a system that is expandable for your future needs. You still need to engage the mobile operators as early as possible. If the operator pays, this is going to be your corporate provider, i.e. you get one operator network supported, think about asking your existing provider about other operators being allowed to connect to the DAS (there are various business models to allow this).

    The good news is, with our solution, we are well placed to meet all these challenges, and help system integrators, operators, and their end customers design the solution that meets their needs, in a cost-effective manner.