Wireless Network Capacity: the Never-Ending Quest
By Howard Baldwin, Contributing Columnist
For quite a few years, experts within the wireless communications industry have been expressing concern about the potential for running out of wireless network capacity. Moreover, FCC Chairman Julius Genachowski noted the ongoing challenges in his 2009 address at CTIA.
In July, the Fortune article, Spectrum Squeeze: The Battle for Bandwidth, envisioned a potential fight for wireless bandwidth frequencies between television networks and telecom service providers. In Canada, earlier in September, Shaw Communications announced it would use Wi-Fi as its next-generation wireless network of choice — in anticipation of future customer demand.
But another option, still in the research phases, is to make the radio frequencies we have assigned to wireless communications now work even harder. Several organizations and educational institutions are taking the R&D path to solving the bandwidth limitation challenge.
Full-Duplex Wireless Solutions
In September, 2011, Rice University engineers announced a wireless breakthrough that it said would allow mobile network operators “to double the throughput in their networks without adding any cellular towers.” Adding what’s known as full-duplex capabilities, which have been available on modems for years, to MIMO (multiple input, multiple output) antennas, engineers can enable wireless devices to send and receive data at the same time.
The value of this technology for network operators: they could continue to use similar equipment with minimal hardware upgrades, according to the Rice professor in charge of the project.
Noise-Cancelling Wireless Solutions
Back in February, researchers at Stanford University said they accomplished a similar capability via a noise cancellation technique. Full-duplex capabilities haven’t been possible because of interference problems. But by implementing a dual-antenna system that works much like noise-cancelling earphones, the engineers have been able to double capacity.
“While not all applications will perform better on a full-duplex network, a VoIP call or video call does need to transmit and receive the same amount of data, and would thereby benefit from this technology,” the researchers noted.
New Infrastructure Deployment Strategies
In Europe, efforts are already underway incorporating improved MIMO and interference techniques, within an initiative called Beyond Next-Generation Mobile Broadband (BuNGee). But its goals are even more ambitious: it wants to increase mobile broadband capacity tenfold.
Using $6.4 million project in funding from the European Commission, a consortium of European service providers, technology equipment vendors, and universities and research organizations is trying to increase the overall mobile network infrastructure capacity up to 1 Gbps per square kilometer.
Besides the aforementioned capabilities, it’s also targeting “backhaul design, below-rooftop backbone solutions, autonomous architectures focusing on very aggressive spatial and spectral reuse and protocol suite facilitating autonomous ultra-high capacity deployment,” according to a 2010 news release. The consortium expects to share the results of its research in 2012.
No matter which technology advancement solves the current problem, it can’t come quickly enough. If there’s one thing about network capacity — especially wireless bandwidth — there’s never enough of it.
Increasing usage of mobile devices is consuming capacity at an accelerated rate, and the ongoing development of miniature wireless sensors — the backbone of the so-called “Internet of things” — stands ready to create new demand for any capacity that’s left over.