AVONDALE, Ariz.--Qualcomm (NASDAQ:QCOM) made the Phoenix International Raceway a test bed for hyper-dense small cell deployment this month during NASCAR's popular Sprint Cup Series, showing how the company's UltraSON software and Qualcomm Atheros chipsets can be used to lay out small cell networks with minimal or no RF planning.
The company laid out 31 Airspan AirSynergy LTE pico base stations in the garage area at the Phoenix track. Christophe Chevallier, principal engineer and manager at Qualcomm, told FierceWirelessTech that the layout represents the "densest LTE outdoor network in the world."
The deployment differs from that of a typical small cell deployment, such as one installed in a shopping mall, where network engineers can plan and optimize the service over time. "Here, you don't have any of that. You install everything, the crowds come and all the teams come. By the time you understand what's going on with the network, they're gone. So this is really unplanned, which is one of the unique aspects of NASCAR," Chevallier said.
Components in the LTE small cells deployed in Phoenix include Qualcomm's baseband system-on-chip chipset, developed by DesignArt Networks (DAN), which Qualcomm acquired in August 2012 and integrated into its Atheros division, as well as Qualcomm-developed self-organizing network (SON) features, which are marketed under the UltraSON brand and run on the Qualcomm's FSM and DAN chipsets.
The Phoenix deployment was made in cooperation with Sprint (NYSE:S) and used 20 MHz of the carrier's 2.5 GHz TDD Band 41 spectrum, with 60 percent of the spectrum allocated to the downlink and 40 MHz to the uplink. Some 45 yellow boxes housing Qualcomm test UEs were distributed throughout the raceway's garage area. The mobile test platforms were based on 8474 and 8974 pro chipsets, more commonly known as the Snapdragon 800 chipset, Qualcomm said.
In addition, Nexus 5 handsets and one LG handset were also used during the tests, resulting in some 60 devices being employed in the test. Service was only available to selected users.
Qualcomm first laid out the small cells in November. Testing has included UltraSON features such as mobility management to reduce frequent ping pong-type handovers between small cells as well as dynamic resource and transmit power management to reduce pilot channel pollution. Chevallier described the resource management function as being based on inter-cell interference coordination (ICIC) between small cells but with an enhancement that enables dynamic portioning.
In this past weekend's technology trial, Qualcomm compared the results it was getting from the TD-LTE deployment to the performance of Sprint's cell-on-wheels (COW), which was delivering commercial FDD LTE services over the operator's 1.9 GHz G-Block spectrum that has a 5x5 MHz pairing. In general, the small cell network delivered 43 times the COW's capacity during the March racing series.
During one demo, the Ookla speed testing site showed that the small cell network enabled a download speed of 21 Mbps while the COW generated only 3 Mbps.
Chevallier said Qualcomm envisions event-based small cell deployments such as the one at the Phoenix raceway remaining in place permanently, unlike COWs, which are usually temporarily deployed for an event and then removed after the event's close. However, in a commercial deployment it would be up to the respective network operator to decide whether or not to do leave the event-specific small cells installed during periods of non-use.
The next time NASCAR returns to the Phoenix area, this coming November, commercial small cells could potentially be deployed for use by racing teams and the general public, said Steve Worling, senior director of IT for NASCAR. He added that NASCAR envisions someday leveraging a VPN service between small cells, tying into Sprint's network for backhaul.
That would be an improvement over the Wi-Fi services currently used by the racing teams, which are subject to traffic congestion and interference over the limited unlicensed spectrum available.
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