TechGuide VIRTUALIZATION CLOUD DEVELOPMENT APPLICATION IT HEALTH NETWORKING ARCHITECTURE STORAGE CENTER MANAGEMENT DATA BI/APPLICATIONS RECOVERY/COMPLIANCE DISASTER SECURITY 1 EDITOR’S NOTE Increasing Wireless 2 LAN Capacity: WLAN CAPACITY Understanding Your Options 3 802.11AD Learn how to increase capacity in your enterprise wireless LAN with 802.11ac and STANDARD explore the uses of 60 GHz wireless technology in the upcoming 802.11ad standard. 4 WLAN PERFORMANCE EDITOR’S NOTE 1 Overcoming WLAN Capacity Challenges The explosion of mobile devices, coupled But speed is only part of the equation. What Home with the growing demand by users for band- 802.11ad really offers is options that give IT width-hungry applications such as HD video, managers greater choice in how they manage Editor’s Note has placed IT managers in a bind. super users and complex applications. Fortunately, help is on the way, in the form That’s latitude managers need as they wrestle WLAN Capacity of new wireless standards that promise much with the challenges of overseeing their WLAN faster throughput and much higher capacity. infrastructures. As demand for video and other 802.11ad Standard The first bit of relief is the rollout of bandwidth-intensive applications grows, IT 802.11ac-compatible devices. Network access managers need a new set of tools to address WLAN points and controllers supporting this stan- their mobile distribution requirements. Performance dard are already available, and smartphones and This handbook provides a detailed examina- tablets capable of transmitting and receiving tion into the next generation of wireless stan- at Gigabit Wi-Fi speeds are now entering the dards and discusses some of the challenges marketplace. Sending data faster requires less IT managers face today with mobile network airtime, which increases the maximum number management. With tablets and smartphones of users per access point. getting more powerful and even more ubiqui- By the end of next year, it’s possible Gigabit tous, crafting a comprehensive WLAN strategy wireless speed will be the foundation and not is more important than ever. n the ceiling. With 802.11ad, wireless through- put soars to 7 Gbps, more than enough to sup- Chuck Moozakis port most bandwidth-intensive applications. Site Editor, Networking Media Group 2 INCREASING WIRELESS LAN CAPACITY: UNDERSTANDING YOUR OPTIONS WLAN CAPACITY 2 New WLAN Standards Promise Faster Data, Higher User Capacity Many enterprise wireless LANs are vic- Wi-Fi certified ac products use faster data Home tims of their own success, challenged to serve rates, more tightly packed transmissions, a skyrocketing population of wireless devices cleaner 5 GHz channels and wider channels Editor’s Note and bandwidth-thirsty applications. To meet to support very high throughput applications escalating demand, WLAN administrators can such as HD video. Specifically, enterprises can WLAN Capacity take a two-prong approach: more efficiently obtain the following improvements by migrat- use existing channels and tap new frequen- ing to 802.11ac: 802.11ad Standard cies to offload bandwidth hogs. Together, these strategies offer hope to enterprises already ap- n Speed: 802.11n data rates top out at 450 WLAN proaching the limits of 802.11n. Mbps to 600 Mbps, using three to four spa- Performance tial streams to deliver traffic. The first wave of 802.11ac products uses the same spatial INCREASING WLAN CAPACITY streams to reach speeds up to 1.3 Gbps. By late WITH DRAFT 802.11AC 2014, the next wave of 802.11ac products will The most immediate step enterprises can take top out at 6.93 Gbps. But real-world results to boost WLAN capacity is to migrate exist- still depend on client capability and distance. ing access points (APs) to 802.11ac. Commonly For example, a single-stream smartphone that known as Gigabit Wi-Fi, the draft 802.11ac transmits at 150 Mbps with 802.11n can be ex- standard further refines advances introduced pected to hit 433 Mbps with 802.11ac. Because by 802.11n, combining them to significantly sending data faster requires one-third as much boost total WLAN capacity. airtime, 802.11ac may permit administrators to 3 INCREASING WIRELESS LAN CAPACITY: UNDERSTANDING YOUR OPTIONS WLAN CAPACITY 2 see a corresponding increase in the maximum n Wider Channels: 802.11n doubled through- number of users per AP. put by combining two 20 MHz-wide channels into one 40 MHz-wide channel. The first wave n Spectral Efficiency: Both 802.11n and 802.11ac of 802.11ac products repeats this by adding use quadrature amplitude modulation (QAM) 80 MHz-wide channels; next year’s second to send data, but 802.11ac can pack four times wave will add 160 MHz-wide channels. Fat- Home as much data into each transmission. Unfor- ter channels do not increase available spec- tunately, 256-QAM only works over short dis- trum—the 5 GHz band is roughly 1 GHz wide, Editor’s Note tances and thus will only quadruple capacity no matter how it’s divvied into channels. But for clients within about 20 feet. doublewide channels give high-throughput ap- WLAN Capacity plications their own express lane in which to n 5 GHz Only: Unlike 802.11n, which oper- move faster, without being impeded by or sap- 802.11ad Standard ates over channels chosen from both the noisy ping bandwidth from slower, latency-sensitive crowded 2.4 GHz band and the less-congested applications. WLAN 5 GHz band, 802.11ac serves clients in the 5 For these reasons, enterprises replacing older Performance GHz band only. Due to reduced interference at 802.11a/g or 802.11n APs with Wi-Fi certified 5 GHz and related radio frequency engineering ac APs are likely to see an immediate increase advances, 802.11ac devices are likely to experi- in WLAN capacity, especially when used by ence a better rate over range than their 802.11n newer smartphones, tablets and notebooks now counterparts, again increasing total WLAN shipping with 802.11ac. Legacy clients won’t capacity. reap all of the standard’s benefits but may still Enterprises replacing older 802.11a/g or 802.11n APs with Wi-Fi certified ac APs are likely to see an immediate increase in WLAN capacity. 4 INCREASING WIRELESS LAN CAPACITY: UNDERSTANDING YOUR OPTIONS WLAN CAPACITY 2 see some improvement, enabling administra- uses to reach data rates up to 7 Gbps. However, tors to increase the total number of devices 802.11ad works its magic over a completely each WLAN can support. When the second different set of channels, thereby increasing wave of 802.11ac products emerge in late 2014, the total spectrum available for WLAN use by multi-user multiple-input multiple-output nearly an order of magnitude. will let each AP converse simultaneously with Home up to four clients, further boosting WLAN capacity. Enterprises will soon be able to slake Editor’s Note escalating bandwidth thirst by using 802.11ad to relocate bandwidth hogs WLAN Capacity ADDING MORE WLAN CAPACITY WITH 802.11AD onto unused 60 GHz channels. Migrating existing WLANs to 802.11ac benefits 802.11ad Standard all Wi-Fi devices and applications. However, certain devices and applications—most notably That said, the 60 GHz channels that 802.11ad WLAN tablets and video—are very demanding, guz- uses are far more limited in range and penetrat- Performance zling limited shared bandwidth. While Quality- ing power. But its properties make 802.11ad of-Service methods like Wi-Fi Multimedia suited for very high throughput communica- help to prioritize traffic and avoid starvation, tion between nearby devices, preferably in the all 802.11ac devices ultimately compete for the same room. Enterprise WLAN administrators same finite patch of 5 GHz channels. may therefore use 802.11ad to expand capac- Fortunately, enterprises will soon be able ity by offloading devices and applications that to slake escalating bandwidth thirst by using thrive under such conditions. Examples include 802.11ad to relocate bandwidth hogs onto un- HD video transmission to wall-mounted wire- used 60 GHz channels. The emerging 802.11ad less displays and sustained communication standard—commonly called WiGig—leverages between desktop-replacement tablets and ex- many of the same technologies that 802.11ac ternal monitors. 5 INCREASING WIRELESS LAN CAPACITY: UNDERSTANDING YOUR OPTIONS WLAN CAPACITY 2 PLANNING FOR CAPACITY increasingly consumed 802.11ac APs. Wi-Fi certified ad products are expected to Ultimately, combining 802.11ac and 802.11ad become available in early 2014. At that point, is like repaving a highway while adding lanes— a growing number of devices will support both both strategies make it possible for more ve- 802.11ac and 802.11ad, enabling both short- hicles to move faster, increasing total capacity. distance and long-distance high-throughput Together, these two standards can help enter- Home communication. Enterprise administrators prise WLAN administrators design and deploy should therefore start thinking about how and new and upgraded networks that deliver sig- Editor’s Note where to best use 802.11ad in the workplace— nificantly higher data rates and amplified user for example, to offload edge-video traffic from density. —Lisa Phifer WLAN Capacity 802.11ad Standard WLAN Performance 6 INCREASING WIRELESS LAN CAPACITY: UNDERSTANDING YOUR OPTIONS 802.11ad STANDARD 3 The 802.11ad Wireless Standard Offers Benefits and Challenges While many enterprises are knee-deep likely to bring the technology mainstream for Home in 802.11n wireless migration, and some are both consumers and the enterprise. even eyeing 802.11ac with its 1.3 Gbps of Editor’s Note throughput, another higher throughput wire- less standard is on the horizon—802.11ad giga- 802.11AD IS SUPER-FAST, WLAN Capacity bit wireless. BUT THERE’S A CATCH Though the technology has its challenges, it The 802.11ad standard is known for its 7 Gbps 802.11ad Standard could supplement existing wireless networks, of throughput, but raw specifications tell only better enabling large-scale BYOD connectivity part of the story.