BROADBAND COMMUNITIES is the leading source of information on digital and broadband technologies for buildings and communities. Our editorial aims to accelerate the deployment of Fiber-To-The-Home and Fiber-To-The-Premises.
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Of course, most 500-bed student Too high a concentration ratio slows down user Internet access, and too low a ratio results in idle bandwidth and excessive costs. Extrapolating the average U.S. speed of 29 Mbps yields the following: YEAR RATE 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 29 44 66 99 149 224 336 504 756 1,134 SCALE Mbps Mbps Mbps Mbps Mbps Mbps Mbps Mbps Mbps Mbps Table 2: Bandwidth Available to U.S. Average Users In this table, 100 Mbps per user de- mand is reached in 2014 and exceeded in 2015. Te numbers in Table 2 are more digestible for student housing network bandwidth predictions – but be aware that student housing demands better-than-average Internet bandwidth. OVERSUBSCRIPTION IN STUDENT HOUSING In most student housing networks, ex- ternal bandwidth is delivered through a gateway device that manages bandwidth shaping and provisioning of end users. Normal industry practice is to apply a concentration ratio or oversubscription rate – to provision 10 users with a 10 Mbps demand rate, an operator would not provision a gateway external con- nection of 100 Mbps but would instead divide that number by the concentra- tion factor. A concentration factor of 10 would require an external bandwidth connection of 10 Mbps in the previous example. Gateway devices also provide rate limiting or bandwidth shaping functionality to ensure fair distribution of resources among active users. Concentration is possible because us- ers rarely, if ever, simultaneously demand the full bandwidth available to them, and traffic patterns such as Web brows- ing are inherently asynchronous with pause times between page demands. Clearly, however, an operator must choose the concentration ratio care- fully. Too high a ratio will result in user slowdown, and too low a ratio will result in idle bandwidth and excessive costs. Concentration ratios can vary substan- tially by class of user, but a 50:1 ratio is not uncommon in student housing. (Increased video streaming will reduce the concentration rates achievable in the future as traffic becomes less asynchro- nous.) Tus, a network with 200 users allocated the U.S. 2011 average of ap- proximately 29 Mbps per user will re- quire external bandwidth of 116 Mbps on its external connection. Applying the growth rates from the possibly understated Nielsen's Law, the throughput that must be handled by the network over the next 10 years is as shown in Table 3. Te numbers are probably meaningful up to 2015. YEAR 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 PER USER 29 43 65 98 147 220 330 495 743 1,114 housing communities today do not pro- vision 290 Mbps to the community. Tat is simply the bandwidth needed to provide the average U.S. download speed to each bed in the community. Most stu- dent housing communities do not pro- vide the 2011 average of 29 Mbps per bed. Indeed, some barely provide 4 Mbps per bed. However, some do provide these speeds, and some exceed them. Tere is a wide differential between the worst and the best bandwidth per bed in student housing. Te top perform- ers in any market – in terms not only of bandwidth but also of ubiquitous avail- ability and close to 100 percent reliability – will see higher occupancy and higher yield. Internet capacity and capability is fast becoming a top requirement for stu- dents when they seek accommodation. AVOIDING RISKS Te major risk to any student housing property or portfolio is a decrease in net operating income through decreased occupancy or rent attrition should a competitor offer better or more reliable Internet service. To mitigate that risk, owners and operators should • Ensure their properties are not locked into term contracts that in- hibit their ability to provide best-in- market services • Ensure sufficient physical infrastruc- ture (wiring and electronics) to de- liver adequate Internet services 200 USERS 116 174 261 391 587 880 1,321 1,981 2.972 4,459 36 | BROADBAND COMMUNITIES | www.broadbandcommunities.com | OCTOBER 2012 500 USERS 290 435 652 978 1,468 2,202 3,303 4,954 7,432 11,148 Table 3: Gateway Bandwidth Requirements SCALE Mbps Mbps Mbps Mbps Mbps Mbps Mbps Mbps Mbps Mbps