Wireless Andrew 2.0 February 13, 2012 Dan McCarriar Director, NICS dlm@cmu.edu Agenda The history of Wireless Andrew Wireless standards 802.11n at Carnegie Mellon Planning the upgrade Deploying the network Deployment and policy issues Wireless stats and adoption Futures Q&A 2 1
History of Wireless Andrew 1994: Began as an NSF-funded research project 1997: Phase I network deployed, covering about 50% of academic spaces 1997: IEEE publishes new 802.11 standard for wireless LANs 1998: Partner with Lucent Technologies, replace everything with newly standardized products, 100% coverage in academic spaces by 1999 2001: Network extended to residence halls, now 100% coverage across campus 2008: Network upgraded to 802.11n 2014:? 3 All-Wireless Campus? Not likely to happen at Carnegie Mellon Though we are seeing demand for wired ports decrease Recently removed more than 300 switch ports from residence halls Currently working on right-sizing the academic/administrative wired network The first wireless-only residence hall went online in Fall 2010 Keep in mind that all of this wireless stuff has a wired network behind it All that said, wireless is probably viable as the primary network for 90% of applications 4 2
Wireless Standards Wireless standards are established by the Institute of Electrical and Electronics Engineers (IEEE) Standard Ratification Date Frequency Max Speed Real Speed 802.11 1997 2.4 GHz 2 Mbps 1 Mbps 802.11b 1999 2.4 GHz 11 Mbps 4-5 Mbps 802.11a 1999 5 GHz 54 Mbps 23 Mbps 802.11g 2003 2.4 GHz 54 Mbps 19 Mbps 802.11n 2009 2.4 or 5 GHz 100-600 Mbps Varies 802.11ac 2013 5 GHz ~ 1Gbps Varies 802.11ad 2010 2.4/5/60 GHz ~ 7Gbps Varies 5 802.11n Technology MIMO Multiple input, multiple output Uses multiple spatial streams to transmit more information over the same frequency using multiple antennae. AxB:C notation. We currently use 3x3:2 radios. Channel Bonding Combines two 20 MHz channels (as used in older 802.11b/g/a standards) into one 40 MHz channel 6 3
Planning the Upgrade Why 802.11n? Last upgrade of Wireless Andrew in 2001 One-time funding available for replacement of entire network, had to be spent by September 08 No funding commitment (yet) for regular equipment refresh Final 802.11n standard was not ratified, but Wi-Fi Alliance was certifying 802.11n draft 2.0 products 7 Planning the Upgrade - Requirements Full coverage in every campus building, both academic/administrative and residences Capacity for advanced applications IP multicast video, VoIP, etc. 802.11n draft 2.0 compliant Also must have a reasonable (i.e. free) upgrade path to the final standard Speed and capacity for wired network replacement 8 4
Planning the Upgrade - Vendor Selection RFP issued April 2007 6 responses On-site vendor conferences with each 3 finalists On-site equipment testing in real-world scenarios Nobody had real 802.11n equipment yet Vendors selected September 2007 Aruba Networks Xirrus 9 Deploying the Network Site Surveys Using AirMagnet Survey product Passive surveys Target -70 RSSI in all spaces Audit with active surveys after product is installed Many tools didn t understand 802.11n yet. We surveyed for an 802.11a deployment. Today, we survey for 802.11n coverage in 5 GHz. 10 5
Deploying the Network Site Surveys Deploying the Network (cont.) Physical Plant Using midspan PoE devices (most 802.11n access points struggle with standard 15.4W 802.3af PoE) Two Cat 5e wires to each access point location Power upgrades in some IDFs Aesthetics of 802.11n access points 12 6
The Aesthetics of 11n 13 The Aesthetics of 11n (cont.) 14 7
The Aesthetics of 11n (cont.) 15 Deploying the Network (cont.) Network Design Location and capacity of controllers (we use a central controller design) We originally thought the central controller design would be an issue. It hasn t been. GigE ports for access points 802.11n in 2.4 GHz vs. 5 GHz vs. both Channel planning 16 8
Deployment Issues DFS2 Support FCC ruling (effective July 2007) governing WLAN systems operating in certain 5 GHz frequencies Need to coexist with military and weather radar 3 rd party lab testing vs. FCC testing 17 Deployment Issues (cont.) 2.4 GHz Ch# 1 6 11 Full DFS2 Support 5 GHz Ch# 36 40 44 48 52 56 60 64 100 104 108 112 116 120 124 128 132 136 140 149 153 157 161 165 18 9
Deployment Issues (cont.) 2.4 GHz Ch# 1 6 11 Full DFS2 Support Bonded Channels 5 GHz Ch# 36 40 44 48 52 56 60 64 100 104 108 112 116 120 124 128 132 136 140 149 153 157 161 165 19 Deployment Issues (cont.) 2.4 GHz Ch# 1 6 11 No DFS2 Support Bonded Channels 5 GHz Ch# 36 40 44 48 52 56 60 64 100 104 108 112 116 120 124 128 132 136 140 149 153 157 161 165 20 10
Policy Issues Guest access to wireless network wide open or controlled? Obvious security issues Possible CALEA implications CMU airspace policy Current policy covers 2.4 GHz Recently updated to cover 5 GHz FCC support for university-owned residences 21 Wireless Stats Two vendors: Aruba Networks and Xirrus Approximately 4.1M sq. ft. of in-building space to cover with wireless 11,000+ unique devices on the wireless network in any given 24-hour period 1717 Aruba AP-125 access points, 8 M3 controllers 348 Xirrus XN8 arrays 22 11
What We re Seeing Clients (2008) 802.11b: 1% 802.11g: 58% 802.11a: 5% 802.11n: 36% 23 What We re Seeing Clients (2012) 802.11b: 0% 802.11g: 12% 802.11a: 1% 802.11n: 87% 24 12
What We re Seeing Speeds (2009) 25 What We re Seeing Speeds (2012) 26 13
Top Issues Client driver updates Enhancements are released regularly, people don t update their software Coverage 100% coverage of indoor areas, but not perfect in some challenging buildings (Wean, etc.) Capacity Number of devices on the network has exploded over the past 4 years This has been more of an issue with IP address pools, large broadcast domains, etc. Occasional issues in large classrooms, events 27 What s Next Enhanced 802.11n outdoor coverage (stadium, Flagstaff, UC courtyard, cut, etc.) WPA2-enabled network ( CMU-SECURE ) 3-stream 802.11n radios, upping max throughput (theoretical) to 450 Mbps 802.11ac/ad Gig wireless Will 4G carrier networks make this all a moot point? 28 14
What s Next (cont.) 802.11r fast handoff between APs via techniques like OKC. Reduces roam time from 200-250ms to 20-25ms. 802.11k radio resource management. APs get info on and advertise their near neighbors (SSIDs, encryption capabilities, load, channels used). 802.11v kitchen sink of client configuration options 29 Q&A Questions? 30 15
Thanks! Dan McCarriar dlm@cmu.edu 16