In-Building Public Access Small Cells

Why do operators need public access small cell solutions?

Mobile users are consuming more data than ever before and the forecasts are that this will continue to grow exponentially for the next few years. Mobile operators are finding that the demand for data services tends to be localised and, therefore, they need to be able to provide solutions for these public areas. These might be hotspots in enclosed spaces, such as a restaurant or shop, or in much larger venues such as airports, stations, shopping malls or stadiums. For the majority of these, the mobile user will be indoors, although some of these extend outdoors.

Enhancing the current mobile network to cater for these hotspots and venues is often just not feasible due to:

Cost of the equipment.
Cost of backhaul.
Cost of installation and maintenance.
Cost of configuration and management.
Limited availability of skilled personnel to carry out the installation.

WiFi has proven successful in providing some data relief in public spaces but will only handle part of the demand, due to its short range, use of unlicensed spectrum (unmanaged interference) and sign-on barriers. The ideal solution is, therefore, one that provides the hotspot with dedicated cellular data and voice capability combined with WiFi where needed.

Benefits

Ubiquisys Public Access Small cells are able to provide concentrated network capacity and deliver the following benefits:

Run over readily available and varying backhaul solutions.
Provide a high capacity solution close to the point of use, to match local concentrations of demand.
A highly cost-effective data network compared with other technologies.
Provide efficient traffic and radio resource management.
Easy to install.
Field-proven – for reliable high traffic and high mobility performance in public spaces.
Small cell hotspot performance – 14.4Mbps HSPA, 16 calls, 250mW, with throughput optimisation for multiple simultaneous data users.
Flexible configuration and siting – multiple backhaul options, optional integrated WiFi hotspot.
Provide Macro-layer adaptation through ActiveRadio™ dynamic interference management and right-sizing of the cell.
Lifecycle management – providing operators complete control of the supply chain, assuring in-service reliability, preserving infrastructure independence and providing a platform for delivering new services.

Capabilities

Ubiquisys Solution Capabilities

Ubiquisys has its ActiveRadio™ technology available for public access hotspots, with a rich set of features including the following:

Listen Mode and Continuous ‘Fast Sniff’.
Uplink Downlink Power Setting and adaptation.
Automatic Neighbour List Creation.
CloudBase™ Service Activation and Software Delivery.
16-call support.
Open or Semi-open Access Modes.
Local IP Access.
Hand Out/Hand In & Cell Stickiness.

For public venues, Ubiquisys ActiveSON™ grid technology provides a fully-self-organising grid of small cells with the following additional functionality:

Enhanced Neighbour Lists.
Automatic Network Repair.
Small Cell Group Management.
Hand In to Border Cells.
Inter-cell Handovers.
Congestion Relief Load Balancing.

ActiveRadio™ Radio Resource Management

Ubiquisys has developed unique radio resource algorithms, which mean that the unit(s) explore the radio environment to optimise the service provided to the user, while at the same time minimising any possible disruption to the external macro network. These algorithms also enable full plug-and-play for the operator by providing the ability to activate and upgrade Small Cells remotely without affecting service.

Provisioning and Automatic Set-up. Small cells are pre-provisioned with basic configuration parameters, so they know who they are and who they belong to. Once plugged in, operator policies are downloaded and the Small Cells simply adjust the radio configuration according to local conditions, within these policies. They are then automatically activated in a matter of minutes.

Listen Mode, UL/DL Power Setting. The Small Cell contains a downlink Listen Mode, which measures the interference levels of surrounding macro and Small Cell cells. Using Listen Mode, the Small Cell selects the settings for optimal performance for users of the Small Cell while minimising the interference to the macro according to the operator’s policies.

Once installed, the Ubiquisys Small Cell uniquely continues to monitor the radio environment and adapts to any changes it encounters.

Dynamic Code and Downlink Power Reallocation. The Small Cell supports downlink power reallocation between individual data channels or between data channels and HSDPA. This means that the Small Cell responds to external interference, optimising the user experience.
Up/Downlink Power Adaptation. The Small Cell initially sets its power levels based on the received signal levels it experiences from the macro network in order to minimise uplink interference, including adjacent channel interference mitigation. These values are then dynamically altered according to the actual levels reported by the end user device through measurement reports.
Continuous Fast Sniff. The Small Cell uniquely uses an active sniff mode during normal operation to monitor changes in the radio environment without affecting calls. When there are significant changes to the radio environment – eg, the addition/removal of a neighbouring cell – the Small Cell will adapt its power levels accordingly.
Power Tuning. In order to ensure that a hotspot cell is attracting the right level of load, or if the load increases and additional capacity is not yet available, the cell can tune its coverage to maintain optimal throughput in the cell.

Capabilities for the end-user

The Ubiquisys Small Cell supports a broad range of call capabilities that meet or exceed mobile operators' needs for Small Cells. Equally of importance, all of these capabilities are already used in live commercial networks and, in the process, have been through rigorous testing and optimisation cycles.

Our public access Small Cells can be optimised to favour either voice coverage or data throughput. This suits mobile operators targeting coverage related market segments, and those who target 3G data performance as a selling proposition.

Below is a brief summary of the key call features we support:

16-Call
Video calling support
Supplementary Services Support
HD voice (WBAMR)
Emergency Calls
HSDPA 14.4 Mbps
HSUPA 5.76 Mbps
Multiple Primary PDP Contexts
Cell FACH
Basic Data Rate Adaptation
Non-Standard UE Profiling & Corrective Actions
Advanced Data Rate Adaptation (Voice priority)

Macro network interworking

Hand Out. Ubiquisys’ Small Cell supports hand out of inter-frequency voice to the 2G (GERAN) or 3G macro network and hand out of video calls from the Small Cell cell to the 3G macro network only. Mobile operators can specify from their management system the priority of the handover type, and who gets the service.

Hand In. The Ubiquisys small cell supports the ability for the macro network to perform connected mode handovers of voice calls and data sessions.

Cell Stickiness. Once a mobile device is camped on to the Small Cell, the Small Cell will endeavour to keep a device attached to the Small Cell layer for as long as possible before hand out to the macro layer.

Automatic Neighbour List Creation. The Ubiquisys Small Cell listens for surrounding 2G and 3G cell sites and creates its own list of neighbouring cells, so mobile phones can seamlessly handout to the surrounding macro network without costly manual configuration back in the network.

Statistics and Diagnostics

The Ubiquisys small cell acts as a part of the mobile network infrastructure at the same time as being an easy to setup and use device. It is configured and provisioned via a standards-based TR-069/196 management system, and provides alarms and performance data according to a DSL Forum specification (TR-096).

Initial connection and registration with the HMS (Home NodeB Management System) is done securely, and, once operating, the small cell gathers performance management (PM) data over a period of time, placing it into a performance report.

Ubiquisys has developed a highly flexible and comprehensive performance management reporting capability as a result of numerous commercial deployments. For example, the management system has full control over which counters are included in the report and the frequency at which the metrics are collected, and when the reports are started, stopped, and uploaded.

Core Network interfacing

Ubiqusys’ small cell engine supports three different network interface protocols for connection to small cell gateways, allowing mobile operators to have the broadest choice of network gateway technologies and suppliers.

Iuh – Ubiquisys was the first company to have standards-compliant Iuh small cells deployed commercially. 
GAN – small cell engine supports the GAN protocols plus the extension for small cell support. This network protocol is used in many commercial networks, with active small cell deployments in the order of hundreds of thousands of units.
IMS – where scalability and cost effectiveness are high priorities, connection directly to an IMS core network, with supporting IMS small cell applications, provides a next generation alternative for operators. This network protocol is commercially deployed, again with hundreds of thousands of units in service.

Lifecycle management

CloudBase™ Software Delivery and Service Activation. The Ubiquisys activation method means that the Small Cell fetches the latest software on activation, and can remotely recover from faults automatically by repeating the activation sequence, or on demand by the management system. This cloud service is delivered by global service delivery partners such as Akamai, Telecity and Flexera.

Lifecycle Management

Ubiquisys ActiveSON™ Grid

In addition to the features set above, Ubiquisys is extending its unique ActiveSON™ Grid solution for public venues where it is beneficial to create a managed layer of overlapping small cell coverage

Enhanced Neighbour Lists. The small cell supports a SON client, which provides the capability to automatically discover and communicate with its peer devices in the local small cell network. This allows the small cell to automatically understand the configuration of its neighbouring small cells, so it can adapt its configuration to provide best service and build ranked neighbour lists for handover.
Automatic adaptation to addition/removal of units. As units are added, removed or occasionally fail, the grid self-adjusts small cell power levels to accommodate new units or fill any gaps.
Small Cell Group Management. Within large venues – eg, a stadium – it may be desirable to form a set of sub-grids to provide services in non-contiguous areas or across more than one zone. In order to facilitate this, the ActiveSON™ grid provides for small cells to be grouped into site and group categories. Connected mode handovers are provided within groups, whilst idle mode mobility is provided between groups. The sites and groups can be any combination of structure up to a total of 200 small cells. The group structure also provides the means to control access to the grid, as groups may be configured to be either in open or closed access mode.
Small Cell to Small Cell Handover. The solution supports intra and inter-frequency handovers, including multi-RAB combinations and cell FACH mobility. For connected mode mobility, small cells can be formed into groups, and handovers within a call (connected mode mobility) are supported between small cells in the same group. This gives an operator a high degree of flexibility in its deployment scenarios. Out of call mobility (Idle mode reselection) is supported across all Small Cell groups, subject to access control restrictions.
Congestion Relief Load Balancing. On congestion (the small cell is at capacity and there is a new mobile originated call), the small cell can either redirect existing calls to other small cells within the same grid group, or make use of cell FACH functionality. The handover target will be based on reported mobile device measurements (if available) or on the strongest neighbour.