Can a mid-sized building have more capacity than a small city?

September 29, 2015

A question to mobile operators: You have just acquired the rights to deploy an indoor system inside a large building and are about to deploy 50+ antennas inside the building. Now, would you like to add a full LTE cell to each antenna? That’s right… would you like a complete LTE single-sector base station where you were planning to install just an antenna? What about two LTE base stations where you were planning to install just an antenna?

Adding an LTE (or 3G) cell in the macro network is expensive, very expensive, and difficult as h*$%! So, rather than getting more cell sites, operators try to increase capacity by buying more spectrum (billions), and improving spectral efficiency (even more billions). As frequent readers of this blog know, SpiderCloud offers a way to add a massive amount of capacity indoors – using scalable small cell systems.

One of SpiderCloud’s customers recently asked our system engineering team to estimate the capacity of a SpiderCloud dual-carrier LTE system. We have a rather sophisticated modeling tool that accounts for interference between small cells and macros, generates randomized distribution of users and more. So, for this analysis, we took an 180,000 ft2 4-floor building. Based on the building’s floor plans, 24 radio nodes were sufficient to provide coverage, and this system was capable of delivering more than 2.5 Gbps of throughput, at less than 50% loading!

diagramblog0915

2.5 Gbps in an 180,000 ft2 is a lot of capacity, enough to stream HD movies to 500 Netflix subscribers simultaneously! Not surprising, since this building has 48 LTE cells, equivalent to 16 3-sector macro base stations, sufficient to cover a small city. Though the actual capacity delivered by a SpiderCloud system will depend upon the backhaul connection commissioned by the operator, adding capacity is as easy as provisioning more backhaul, a topic we discussed in a previous post.

SpiderCloud’s approach is very different from big macro base stations vendors, all of whom are still looking for a way to somehow make their macro base station technology (Dots, Lamps, and everything else) applicable to indoor. Macro base station roadmaps are rightfully designed to incrementally squeeze more bps out of existing macro cell site grid, and more $$s out of operators. The whole point is to sell the operator increasingly expensive-to-deploy features like coordinated multipoint and 4×4 MIMO on existing platforms – basically, a gravy train for the big vendors, a sink-hole for their customers.

SpiderCloud’s offers a disruptive alternative – a really easy to deploy system with so much capacity on day one that our customers do not have to buy a capacity upgrade for a very, very long time.

– Art King, SpiderCloud Wireless, Director of Enterprise Services & Technologies
– Amit Jain, Vice President of Marketing & Product Management

Twitter: @EMobilityInside
Visit our Enterprise IT site @ http://SpiderCloud.com/EInsider


Fact Check: Adding Capacity in an E-RAN System

August 24, 2015

We have encountered a number of incorrect opinions about how to add capacity to an E-RAN installation. It’s time to clarify the concerns, and set the record straight.

Adding capacity to an E-RAN installation is done by increasing the size of backhaul connecting it to the mobile core. Further, the contemporary Ethernet Network Termination Equipment “NTE” that are implemented by Tier One operators, adding capacity is performed by an OSS system by increasing the logical rate on a 1Gbps Ethernet physical port. There is no need to visit the building, add additional Radio Nodes and cabling, or install new cards in a chassis.

In the balance of this post, we review the E-RAN technical characteristics that support the approach of increasing backhaul to add capacity to an E-RAN.

E-RAN Technical

  • Each SpiderCloud Radio Node (SCRN-310) offers 2 cells (sectors) of capacity, and supports up to 128 active users.
  • Up to 100 SCRN-310s can be connected to a Services Node. The Services Node supports over 10,000 subscribers.
  • The number of Radio Nodes in a building is based on coverage. Each radio node covers 750-1000 sq. m. (7,500-10,000 sq. ft.).
  • A single 20Mhz wide LTE carrier can deliver up to 150Mbps of downlink to a mobile device.
  • The fronthaul network supporting the cloud of Radio Nodes associated with a Services Node is typically a 1Gb PoE+ link to an Ethernet VLAN with a 10Gbps backbone that interconnects the switches.

To make sense of this, typical commercial structures in the USA and Europe allocate anywhere from 15-25 sq. m. per person (150-250 sq. ft.) and, for purposes of this Fact Check, we’ll use a density of 10 sq. m. per person. This means that the maximum population supported by a single RN-310 with 750 sq. m. of coverage will be 75 people – of which only a small amount will be consuming capacity from their serving Radio Node at any moment in time.

Clearly, there is a huge amount of RF link capacity available to serve the mobile devices in this example. Note that each RN provides more capacity to a 1,000 sq. m. area than many DAS (or remote radio head systems) provide to a 10,000 sq. m. building. We shared, in this post, our view of spectrum re-use and how the E-RAN is analogous to the wired network revolution that was led by the emergence of 10Base-T and Ethernet switches.

In our experience, there is rarely a situation in which an operator has to add a Radio Node due to RF resource contention.

Now, let’s look at the backhaul that connects the Services Node to the mobile core. When an E-RAN system is viewed from end to end, the sizing of the backhaul is generally the bottleneck in any performance scenario. What limits the capacity of an E-RAN system is the backhaul that the operator delivers. If the operator delivers 100 Mbps of backhaul to an E-RAN with 20 RNs, it will operate at <5% of its capacity. If an operator wants to add capacity to an E-RAN, all they need to do is to increase the backhaul coming into the building.

Fact Check Recap:
Question: How do you add capacity to an E-RAN?
Answer: Increase the size of the backhaul as-needed. No truck rolls or on-site work required.

To our readers, if you have additional questions or areas of interest around implementation, please contact us. We’re happy to Fact Check what you may have been told.

– Art King, SpiderCloud Wireless, Director of Enterprise Services & Technologies

Twitter: @EMobilityInside
Visit our Enterprise IT site @ http://SpiderCloud.com/EInsider