- Increased productivity and more relaxed employee
- Flexibility to work when they want, where they want
- Reduce costs
- Adapt to changing needs and technologies
Types of wireless ( by distance)
- Wireless Personal-Area Networks(WPAN-a few feet) : Bluetooth or Wifi Direct-enabled devices are used in WPANs
- Wireless LANs( WLANs-a few hundred feet): in room, home, office and campus.
- Wireless Wide-Area Networks (WWANs- miles) metropolitan area, cellular hierarchy.
Ranges of frequencies, called bands, are allocated for various purposes.
- Some bands in the electromagnetic spectrum are heavily regulated and are used for applications, such as air traffic control and emergency responder communications networks.
- Other bands are license free, such as the Industrial, Scientific, and Medical (ISM) and the Unlicensed national information infrastructure (UNII) frequency bands.
Note: WLAN networks operate in the ISM 2.4 GHz frequency band and the UNII 5 GHz band.
The radio waves range is subdivided into a Radio frequencies and Microwave Frequencies
- Very low frequency(VLF) : submarine communication
- wireless heart rate monitors
- Radio navigation
- Low frequencies(LF):
- AM radio
- Medium Frequency(MF)
- AM radio
- Avalanche beacons
- High frequency(HF)
- Shortwave Radio
- citizens’ band radio
- Marine and mobile radio telephone
- Very high frequency( VHF)
- FM radio
- VHF television
- Ultra High Frequency(UHF)
- WLAN (2.4GHZ)
- Cellular broadband
- UHF TV
- Microwave ovens
- GPS system
- Super high frequencies(SHF)
- Microwave communication
- Satellite communication
- Radio astronomy
- Extremely high Frequency(EHF)
- WiGig WLANs(60GHZ)
- Radar landing systems
- Radio astronomy
WLANs, Bluetooth, cellular, and satellite communication all operate in the microwave UHF, SHF, and EHF ranges.
Wireless LAN devices have transmitters and receivers tuned to specific frequencies of the radio waves range. Specifically, the following frequency bands are allocated to 802.11 wireless LANs:
- 2.4 GHz (UHF) – 802.11b/g/n/ad
- 5 GHz (SHF) – 802.11a/n/ac/ad
- 60 GHz (EHF) – 802.11ad
IEEE 802.11n – Released in 2009, it operates in the 2.4 GHz and 5 GHz frequency bands and is referred to as a dual-band device. Typical data rates range from 150 Mb/s to 600 Mb/s with a distance range of up to 70 m (.5 mile). However, to achieve the higher speeds, APs and wireless clients require multiple antennas using the multiple-input and multiple-output (MIMO) technology. MIMO use multiple antennas as both the transmitter and receiver to improve communication performance. Up to four antennas can be supported.
IEEE 802.11ac – Released in 2013, operates in the 5 GHz frequency band and provides data rates ranging from 450 Mb/s to 1.3 Gb/s (1300 Mb/s). It uses MIMO technology to improve communication performance. Up to eight antennas can be supported. The 802.11ac standard is backward compatible with 802.11a/n devices; however, supporting a mixed environment limits the expected data rates.
IEEE 802.11ad – Scheduled for release in 2014 and also known as “WiGig”, it uses a tri-band Wi-Fi solution using 2.4 GHz, 5 GHz, and 60 GHz, and offers theoretical speeds of up to 7 Gb/s. However, the 60 GHz band is a line-of-site technology and; therefore, cannot penetrate through walls. When a user is roaming, the device switches to the lower 2.4 GHz and 5 GHz bands. It is backward compatible with existing Wi-Fi devices. However supporting a mixed environment limits the expected data rates.
Three organizations influencing WLAN standards are:
- ITU-R – Regulates the allocation of the RF spectrum and satellite orbits.
- IEEE – Specifies how RF is modulated to carry information. It maintains the standards for local and metropolitan area networks (MAN) with the IEEE 802 LAN/MAN family of standards. The dominant standards in the IEEE 802 family are 802.3 Ethernet and 802.11 WLAN. Although the IEEE has specified standards for RF modulation devices, it has not specified manufacturing standards; therefore, interpretations of the 802.11 standards by different vendors can cause interoperability problems between their devices.
- Wi-Fi Alliance – The Wi-Fi Alliance® (http://www.wi-fi.org) is a global, non-profit, industry trade association devoted to promoting the growth and acceptance of WLANs. It is an association of vendors whose objective is to improve the interoperability of products that are based on the 802.11 standard by certifying vendors for conformance to industry norms and adherence to standards.
- IEEE 802.11a/b/g/n/ac/ad compatible
- IEEE 802.11i secure using WPA2™ and Extensible Authentication Protocol (EAP)
- Wi-Fi Protected Setup (WPS) to simplify device connections
- Wi-Fi Direct to share media between devices
- Wi-Fi Passpoint to simplify securely connecting to Wi-Fi hotspot networks
- Wi-Fi Miracast to seamlessly display video between devices
Components of WLANs
- End devices with wireless NICs： Mobile device laptop include integrated wireless NICs, if not , a USB wireless adapter can be used
Powerline: use electrical infrastructure to transfer the network signal. PLE400(1 port), PLS400( 4 ports) PLW400( 1 port and support 8 wireless device)
- Infrastructure device, such as a wireless router or wireless AP:
- Autonomous APs: Standalone devices configured using the Cisco CLI or a GUI. Best for only a couple of APs. home router is an example.
- Controller-Based APs: Server-dependent devices that require no initial configuration. Each AP is automatically configured and managed by a WLAN controller.
Small business wireless deployment requirements, autonomous AP solutions:
- Cisco WAP4410N AP – This AP is ideal for small organization requiring two APs and supporting a small group of users.
- Cisco WAP121 and WAP321 APs – These APs are ideal for small organizations that want to simplify their wireless deployment using several APs.
- Cisco AP541N AP – This AP is ideal for small- to mid-sized organizations that want robust and an easily manageable cluster of APs.
Note: Most enterprise-level APs support PoE.
Solutions for small or big company
The cluster provides a single point of administration and enables the administrator to view the deployment of APs as a single wireless network, rather than a series of separate wireless devices. The clustering capability makes it easy to set up, configure, and manage a growing wireless network. Multiple APs can be deployed and push a single configuration to all the devices within the cluster, managing the wireless network as a single system without worrying about interference between APs, and without configuring each AP as a separate device.
A cluster can be formed between two APs if the following conditions are met:
- Clustering mode is enabled on the APs.
- The APs joining the cluster have the same Cluster Name.
- The APs are connected on the same network segment.
- The APs use the same radio mode (i.e., both radios use 802.11n.).
WAP121, WAP321, and AP541N APs support the clustering of APs without the use of a controller.
Cisco Meraki Cloud Managed Architecture
APs are managed centrally from a controller in the cloud. Cloud networking and management provides centralized management, visibility, and control without the cost and complexity of controller appliances or overlay management software.
This process reduces costs and complexity. The controller pushes management settings, such as firmware updates, security settings, wireless network, and SSIDs settings to the Meraki APs.
Note: Only management data flows through the Meraki cloud infrastructure. No user traffic passes through Meraki’s datacenters.
- Cisco MR Cloud Managed Wireless APs – Various models exist to address a broad range of wireless deployment.
- Meraki Cloud Controller (MCC) – The MCC provides centralized management, optimization, and monitoring of a Meraki WLAN system. The MCC is not an appliance that must be purchased and installed to manage wireless APs. Rather, the MCC is a cloud-based service that constantly monitors, optimizes, and reports the behavior of the network.
- Web-based Dashboard – Meraki’s web-based Dashboard performs configuration and diagnostics remotely.
Cisco Unified Wireless Network Architecture
The Cisco Unified wireless network architecture solution, using a split MAC design, controls APs using a WLAN controller (WLC) and can be optionally managed using Cisco Wireless Control Systems (WCS). The lightweight APs communicate with the WLAN controller using the Lightweight Access Control Point Protocol (LWAPP). The controller has all of the intelligence for communication and the AP is a “dumb terminal” that simply processes packets.
- Lightweight APs – Cisco Aironet 1600, 2600, or 3600 wireless APs models provide robust, dependable wireless network access for hosts.
- Controllers for small and medium-sized businesses – Cisco 2500 Series Wireless Controllers, Cisco Virtual Wireless Controller, or the Cisco Wireless Controller Module for Cisco ISR G2 provide small branch or single-site enterprise WLAN deployments with entry-level wireless for data.