Monday, 15 July 2013
Friday, 8 March 2013
A bit more detailed presentation on the same topic by Ruckus is also embedded below:
- Wi-Fi & Packet Core (EPC) Integration
- Hotspot 2.0, Next Generation Hotspot (NGH), etc.
- Cellular-Wi-Fi Integration - technology and standardization roadmap
Tuesday, 8 May 2012
Friday, 22 August 2008
According to the book "WI-Fi, Bluetooth, Zigbee and Wimax":
802.11n is the 4th generation of wireless lan technology.
- First generation (IEEE 802.11) since 1997 (WLAN/1G)
- Second generation (IEEE 802.11b) since 1998 (WLAN/2G)
- Third generation (802.11a/g) since 2000 (WLAN/3G)
- Fourth generation (IEEE 802.11n) (WLAN/4G)
The distinguishing features of 802.11n are:
- Very high throughput (some hundreds of Mbps)
- Long distances at high data rates (equivalent to IEEE 802.11b at 500 Mbps)
- Use of robust technologies (e.g. multiple-input multiple-output [MIMO]and space time coding).
In the N option, the real data throughput is estimated to reach a theoretical 540 Mbps (which may require an even higher raw data rate at the physical layer), and should be up to 100 times faster than IEEE 802.11b, and well over ten times faster than IEEE 802.11a or IEEE 802.11g. IEEE 802.11n will probably offer a better operating distance than current networks. IEEE 802.11n builds upon previous IEEE 802.11 standards by adding MIMO. MIMO uses multiple transmitter and receiver antennae to allowfor increased data throughput through spatial multiplexing and increased range by exploiting the spatial diversity and powerful coding schemes. The N system is strongly based on the IEEE 802.11e QoS specification to improve bandwidth performance. The system supports basebands width of 20 or 40MHz.
Note that there is 802.11n PHY and 802.11n MAC that will be required to acheive 540Mbps.
To achieve maximum throughput a pure 802.11n 5 GHz network is recommended. The 5 GHz band has substantial capacity due to many non-overlapping radio channels and less radio interference as compared to the 2.4 GHz band. An all-802.11n network may be impractical, however, as existing laptops generally have 802.11b/g radios which must be replaced if they are to operate on the network. Consequently, it may be more practical to operate a mixed 802.11b/g/n network until 802.11n hardware becomes more prevalent. In a mixed-mode system, it’s generally best to utilize a dual-radio access point and place the 802.11b/g traffic on the 2.4 GHz radio and the 802.11n traffic on the 5 GHz radio.
A lot of phones are coming with inbuilt WiFi (or 802.11 a/b/g) and this WiFi is a must on Laptops or they wont sell. The main difference in 802.11n, compared to previous generation of 802.11 is that there is a presence of MIMO. 802.11 family uses OFDM which is the same technology being adopted by LTE. The new LTE handsets will have advantage of easily integrating this 802.11n technology and the same antennas can be reused. In fact the same is applicable for WiMAX as it supports MIMO and OFDM. Ofcourse we will have problems if they are using quite different frequencies as the antennas ore optimised to range of frequencies, this is something that has to be seen.
In the news:
MIT and a medical center based in Alabama are beginning to deploy faster wireless 802.11n access points from Cisco Systems Inc. In more than 100 buildings on MIT's Cambridge, Mass., campus, as many as 3,200 access points running older 802.11a/b/g protocols will be replaced with 802.11n devices in the next 12 to 16 months, said Chris Murphy, a networking engineer at the university. Murphy said MIT, with more than 10,000 students and 11,000 staff members, has a "very, very wide variety" of client devices, from handhelds to laptops. Many of the laptops probably support the 802.11n protocol, he said. Some MIT staffers have been using voice-over-IP wireless handsets and have experienced poor coverage with the older Wi-Fi technology, but they said they have had full signal strength within the range of the new 802.11n access points, he added. With 802.11n, the university could eventually provide IP television, which requires a lot of bandwidth, Murphy said.
Using 802.11n technology, Lapham said he was able to transmit a gigabyte of data in less than two minutes. Currently, the 370-bed medical center has about 450 access points on older protocols. Devices used on the wireless network include 180 laptops, which are used primarily for transmitting bedside patient data. The hospital also supports 100 VoIP wireless phones and a various medical devices.
Wi-Fi is expected to be available in 99 per cent of North American universities by 2013, according to research released by industry analyst ABI Research this week. Much of that penetration will be in the form of 802.11n equipment: higher education is clearly the number one market for early adopters of 802.11n, the company said.
ABI Research expects 802.11n uptake – which is today fairly small in the education market – to ramp up steeply to quite a high rate of penetration," said ABI Research vice president Stan Schatt. There are several reasons for this. ABI said many students now assume a campus Wi-Fi network as a given, and many of their shiny new laptops will be 'n'-compatible. Universities also have great bandwidth demands, as lecture halls may need to serve a large number of users with multimedia contention at any given time and 802.11n's greater speed and capacity can address that need. Moreover, said Schatt, "Universities are breaking new ground by using video over Wi-Fi in a number innovative ways. This is driving the adoption of high speed 802.11n. Students in the near future (at least the diligent ones) will be just as likely to watch their favourite professor's lectures on their laptops as they will be to view 'America's Next Top Model'."
You may also be interested in reading:
- Wireless Handheld Devices--The 802.11n Advantage - Embedded.com
- 802.11n delivers developing ecosystem - EE Times
- Emerging Technologies in Wireless LANs - Benny Bing
Sunday, 23 March 2008
- 802.11a - 54 Mbps standard, 5 GHz signaling (ratified 1999)
- 802.11b - 11 Mbps standard, 2.4 GHz signaling (1999)
- 802.11c - operation of bridge connections (moved to 802.1)
- 802.11d - worldwide compliance with regulations for use of wireless signalspectrum (2001)
- 802.11e - Quality of Service (QoS) support (2005)
- 802.11f – Inter access point protocol to support roaming clients (2003)
- 802.11g - 54 Mbps standard, 2.4 GHz signaling (2003)
- 802.11h - Enhanced version of 802.11a to support European regulatory requirements (2003)
- 802.11i - Security improvements for the 802.11 family (2004)
- 802.11j - Enhancements to 5 GHz signaling to support Japan regulatoryrequirements (2004)
- 802.11k - WLAN system management
- 802.11l - Skipped to avoid confusion with 802.11i
- 802.11m - Maintenance of 802.11 family documentation
- 802.11n - Future 100+ Mbps standard
- 802.11o – Voice over WLAN, faster handoff, prioritize voice traffic over data
- 802.11p – Using 5.9GHz band for ITS (long range)
- 802.11q – Support for VLAN 802.11r – Handling fast handoff when roaming between APs
- 802.11s – Self-healing/self-configuring mesh networks
- 802.11t - Wireless Performance Prediction
- 802.11u - Interworking with External Networks
- 802.11v - Wireless Network Management standard
- 802.11w - Protected Management Frames standard
- 802.11x – Summarize all 802.11 standards, but it is not a standard.
- 802.11y - Contention Based Protocol Study Group
- 3G4G website
- 802.11 Wireless Standards Defined and Discussed By Lee Badman
- 802.11 WLAN Systems – a tutorial