802.11ac was introduced to handle the boom in devices that need to use a wireless network at faster speeds. Whereas we would still argue that you can’t beat a lan cable for the fastest and most reliable network connections, you can’t get away from the fact that the vast majority of users prefer the mobility that a wireless network offers; this is especially true where the client device is a phone or tablet.
802.11ac is the next evolution in wireless technology, going forward from 11n which has been around since 2009. 11ac wireless technology represents a significant performance increase over its highly successful predecessor, 802.11n. The 802.11ac IEEE standard allows for theoretical speeds up to 6.9 Gbps in the 5-GHz band, or 11.5 times those of 802.11n. The first draft 802.11ac was ratified in Jan 2014 (referred to as Wave 1) with PHY* rate speeds up to 1.3Gbps. Wave 2 is the second release of 11ac products which is hitting the streets in late 2016 and promises some new, exciting features with PHY* rate speeds up to 3.47Gbs (well in some countries anyway!). However the full IEEE specification for 11ac actually allows a PHY rate up to 6.9Gbps; assuming, of course, that there’s the frequency bandwidth to support such things! Continue reading…
With the increasing importance of wireless networks in the corporate, educational and hospitality world and the proliferation of WiFi infrastructure to service these demands, it has become even more important that the network administrator has the tools at hand to quickly manage, configure and generally administer the various elements of the network. At its most basic this might be simply to change the SSID of one particular access point (AP) or, at the other end of the scale, it might be to en-mass administer a firmware update; the ability to centrally control and manage all elements of the WiFi network is now a vital tool for any system where there is a large, distributed wireless infrastructure.
The basic elements of any managed wireless system is a collection of distributed access points (APs) which connect through wired network connections to the access controller (AC). The access controller is the device or server which facilitates control functions of the APs. The AC unit can take the form of a stand alone controller, a WLAN switch, or even a computer/software implementation. Although a wired network would be the norm for control connectivity to the access points, it is also possible to use a secondary wireless infrastructure for the data connectivity.
Fat, Thin, and Fit APs
In a managed WiFi network, consisting of multiple access points and the access controller, the level of data control and management the AC has to furnish depends upon the level of autonomous operation the APs have. Continue reading…
Wireless networking typically uses the unlicensed 2.4-2.5GHz or, more recently, 5.1-5.8GHz frequency band though the 2.4GHz is still the most popular form of radio based networking. The range of kit is massive with many hundreds of competitive kit available from simple USB cards for notebook computers up to powerful bridging units designed to link buildings.
Before the 802.11b protocol appeared in 1999, LAN networking meant you had to be physically connected via a cable. The family of 802.11 protocols are made up of an arrangement of over-the-air modulation techniques that use the same basic principles. The most widely used protocols are the 802.11b, 802.11g and 802.11n for 2.4GHz networks and the 802.11a, 802.11n and 802.11ac for 5GHz networks.
802.11 Operating Modes
Infrastructure Mode is used when there is at least one Wireless Access Point and client. The client connects to the network through the Access Point. So, for two clients to talk to each other they do so by routing through the access point. Continue reading…
This article suggests possible scenarios for delivering broadcast WiFi for public areas such as holiday parks, caravan sites and marinas. I also discuss what you can do for user management. The purposes of this management could be so you can offer a chargeable service and/or so you can control and have traceability for site visits and usage: This final point might well be something that you need if Ofcom come knocking on your door accusing you of downloading a rip off DVD through your internet connection!
The WiFi broadcast methods discussed here centre around scattering WiFi nodes around the site to give complete WiFi coverage. However, before going through the various methods to achieve this, first of all we need to discuss the issues of where a signal will reach and where it will not. They key point is wireless doesn’t go through walls or buildings or caravans! So you need to mount your outdoor wireless devices so that users can get clear line of sight to where the WiFi is being sent from. If the user is in a caravan or a metal hulled boat then that means the window of the caravan/boat needs to be aimed at where the WiFi is coming from. This means, when covering a park or ‘van site, that you need to scatter WiFi transmitter nodes around the site to give all users clear connectivity. Of course you also want to keep the number of nodes down to reduce interference, boost throughput and to reduce costs. Deciding how many WiFi nodes to install and where to mount them for optimum coverage is, in my opinion, the hard part!
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Traditional Homeplug is a method of transmitting network data down standard mains powered cables. So the network data is overlaid onto the mains signals. Typical applications are networking around the home via the mains sockets. This is the application of Homeplug that 99% of people are familiar with. However, it is also possible to send Homeplug signals down other cable types; the Homeplug technology is flexible and independent of the cable type or the infrastructure used for the transport of the signals – you just need to make sure that the product has the necessary hardware interface specific to the type of cabling or transport infrastructure you want to use the units on. So with the correct hardware interface on the Homeplug units you could, for example, use Homeplug networking down coaxial cable or standard twisted pair wire. The advantages of Homeplug over more dedicated cabling, compared to over active mains cables, are much higher data transmission rates and longer cable runs. The electrical noise invariably present on normal mains wiring and the complications present in how the cable is distributed (spurs, consumer units etc) often limits the effective data speed and also restricts the length of cable runs you can get away with. Homeplug over, for example, twisted pair wire can give TCP data throughputs in excess of 25Mbps with cable runs of 500m.