steve asked:


Expensive RF analysis tools are available to measure a variety of parameters that only an RF engineer has a clue what they mean and the implications of their values. But when it comes to networks — wired or wireless — ultimately, what one should be most interested in is throughput performance. 802.11 (i.e. Wi-Fi) is a robust standard that includes a variety of protocols that help it communicate wirelessly with other devices. Unless one has intimate knowledge of the 802.11 standard and its inner workings, then it is not possible to predict how an 802.11 network will behave when you are armed solely with RF measurements. This is why it is important to focus on performance metrics — since these more accurately predict how a wireless network will actually behave in a real-world environment.

What follows is a brief introduction to 4 troubleshooting techniques (network discovery, RF spectrum analysis, WiFi channel analysis, and WiFi connection analysis). We begin with a summary of the pros and cons of the different troubleshooting techniques, which should give you a high-level view of the direction in which the field of WiFi diagnostics is currently headed:

Summary:

1. Network Discovery:

Advantages: Inexpensive

Disadvantages: Of limited use since it only detects beacon packets transmitted by 802.11 access points. It does not “see” or measure RF energy transmitted by non-802.11 devices (which dominate the RF environment) or, even, actively transmitting 802.11 stations.

2. RF Spectrum Analysis:

Advantages: Detects all RF transmissions within a frequency band. Based on the transmission pattern you might be able to identify the source of the interference.

Disadvantages: Expensive — since it requires proprietary hardware. When it detects RF interference in the 2.4x or 5.x GHz ISM bands, it can not predict how this will affect 802.11 devices or WiFi network performance — since it knows nothing about the 802.11 standard nor how its underlying protocols work to mitigate potential sources of interference.

3. WiFi Channel Analysis:

Advantages: Inexpensive — uses off-the-shelf 802.11 devices. Measures RF interference through the eyes of an 802.11 device — hence, can better predict how an 802.11 Wi-Fi network will actually perform in the current environment. Can quantify the expected performance for each Wi-Fi channel, thereby allowing you to choose the optimal channel.

Disadvantages: Of limited use when attempting to identify the source of interference.

4. Connection Analysis:

Advantages: Inexpensive — uses off-the-shelf 802.11 devices or your built-in 802.11 adapters. Measures throughput performance of your 802.11 devices when connected to a Wi-Fi network — which is the ultimate metric when it comes to troubleshooting a network.

Disadvantages: Of limited use when attempting to identify the source of interference.

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Descriptions:

1. Network Discovery An 802.11 network discovery tool will report the Service Set Identifier (SSID) for each access point (AP) it detects, along with the channel used by the AP. Approximately every 100 mSec an AP transmits a small beacon packet and a discovery tool (running on your laptop and using its 802.11 wireless adapter) detects the beacon and adds the packet information (including the AP’s SSID) to its list of known access points. In addition, the discovery utility may report signal strength (in dBm units) of the beacon as detected by the client adapter. The beacon’s signal strength is a reflection of how close the AP is to your current location. Though this is useful information, it does not tell you anything about non-802.11 devices or even how busy the access points are. That is, your laptop could be sitting next to a microwave oven and the discovery tool would be clueless as to its existence. The discovery tool only knows about beacon packets transmitted by 802.11 devices and can not see non-802.11 transmissions.

Network discovery tools use the 802.11 adapter built into your laptop or an external USB 802.11 adapter. Since they do not require additional proprietary hardware, then they are relatively inexpensive (even free).

AP Beacon Strength Is Not A Measure Of Performance

The signal strength reported by a network discovery tool is the signal strength of a beacon as measured by the 802.11 wireless adapter installed on your laptop or desktop machine. Each access point (AP) sends out a short pulse or beacon of information approximately every 100 mSec. It’s equivalent to an ‘I’m over here!’ shout. It does not expect a response from the 802.11 client adapters that may hear it — it’s just a one-way shout. The signal strength that the network discovery tool reports is the signal strength of a beacon, and the signal strength of a beacon is a reflection of how close that AP is located to you. It is not a reflection of the performance or throughput you can expect by associating with that AP — rather, it is an indication of the AP’s physical location relative to you. If the AP with the strongest beacon has 24 client adapters associated with it that are actively transmitting and receiving information, and if you connect with that AP then you will be client number 25 and your network connection will seem slow. On the other hand, if you instead choose to associate with an AP whose beacon strength is weaker but which is not associated with other client adapters, then you will likely experience better performance. Furthermore, the AP with the strongest beacon signal may be using a channel that is subject to RF interference — again, degrading its performance. When it comes to networking (both wired and wireless) what we care most about is performance. And the key to performance is ‘throughput’ (i.e. bytes-per-second). Though a beacon’s signal strength can affect it’s performance, what’s more important is the number of client stations that are competing for the same AP and whether the channel currently used by the AP is subject to RF interference from other wireless devices in the vicinity.

2. RF Spectrum Analysis An RF spectrum analyzer is the instrument of choice for detecting and identifying sources of RF interference. Spectrum analyzers are a basic tool used for observing radio frequency (RF) signals. Since they detect all RF transmissions (both 802.11 and non-802.11) then they provide a much better picture of the RF environment, which then helps you identify and, perhaps, locate devices that could be interfering with your Wi-Fi network. Typically an RF spectrum analyzer will employ a 2-dimensional display where the vertical axis (Y-axis) represents the strength of a signal and the horizontal axis (X-axis) represents the frequency of a signal. If the spectral trace of the interfering RF transmissions have previously been documented, then it might be possible to determine which type of device is causing the disturbance. As for tracking-down and attempting to locate an interferer, in practice this is more difficult than it might seem on the surface. Not only does it require the use of a directional antenna, but in an indoor environment with waves bouncing all over the place (off of objects and walls) then how do you discern from which direction the wave originated. In other words, when your directional antenna measures a signal from a wave you don’t know whether that’s the original wave or the result of a wave that has bounced off of an object or wall in the room.

3. WiFi Channel Analysis Today, one of the hottest topics discussed by Wi-Fi infrastructure manufacturers is “using the infrastructure to troubleshoot the infrastructure”. That is — using 802.11 devices to troubleshoot an 802.11 network. Channel analysis is a new technique we have championed and pioneered. This type of tool uses 802.11 hardware to perform data acquisition — hence, the results truly reflect how RF interference in the local environment affects throughput performance of 802.11 channels. This is not possible using an RF spectrum analyzer. By virtue of the fact an 802.11 channel analyzer views the RF world through the eyes of an 802.11 device, then the diagnostic information it provides more closely mirrors the performance you can expect from your own 802.11 client adapters. This makes it easier to troubleshoot and fix problems and allows you to make better-informed decisions regarding how best to configure your wireless network for optimal throughput performance.

4. Connection Analysis Ultimately, the bottom line for any network (wired or wireless) comes down to throughput performance — that is, how many bytes-per-sec can be transferred from one node on the network to another. The dBm and RSSI values that are often referred to in the context of wireless networks don’t mean much if you can’t somehow relate them to a performance metric. Before we can really begin to troubleshoot a wireless network we need a way to benchmark its performance, so as modifications are made we can determine whether or not they really make a difference in the network’s performance. A connection analysis tool allows you to directly compare the performance and reliability of different combinations of 802.11 adapters and access points.

Kamlesh Patel asked:


s use encrypted technology that enables secure voice and data transfer during calls. GSM technology uses an algorithm to ensure the authenticity of the caller and the integrity of the channel, even when you are roaming in a foreign country.

The most interesting, and potentially contentious area of wireless security is that concerning wireless LANs or Wi-Fi networks, these are fast becoming the connection method of choice. Wireless signals do not recognize corporate or geographical boundaries and are only limited by the propagation configuration of the network. Even in an office environment you will find small areas or “blind spots” where the coverage is very weak or non-existent. So, it is possible for the random surfer to “happen upon” on someone else’s network. How can one protect against this happening?

Wireless local area networks use spread-spectrum technology – a technique that makes the radio signals difficult to intercept. Most Wi-Fi systems also include a form of user logon and password protection. Of course, the spread spectrum signals can be intercepted with a relatively simple wireless card and many networks do not properly set up the password feature and will allow ready access to anyone. The fact that “employees” have to go through some form of physical security before they can access the network only adds to the notion that wireless networks may not be as secure as equipment manufacturers would have us believe.

The problem with wireless security is essentially a technical issue with the way the signals are encrypted. The original wireless LANs (WLANs) used the Wireless Encryption Protocol (WEP). This was then replaced in late 2002 with the Wi-Fi Protected Access (WPA). Essentially, WPA offered improved data encryption through the use of temporal key integrity protocol (TKIP). The TKIP feature scrambles the keys using a hashing algorithm and ensures that the keys have not been tampered with. WEP only uses a static key that is seldom changed by users. This cryptographic weakness caused many of the security breaches in WLANs because intruders could, with relative ease, generate an encryption key and access a wireless network.

While WPA offers enhanced security features over WEP, not all industry observers are completely satisfied. A recent problem was highlighted with WPA concerning the use of poorly chosen passwords for a network. Criminals intent on compromising a WLAN can use simple dictionary software to overcome the system password. In fairness, this weakness only manifests itself when short, text-based keys are used and does not signify a fault in the WPA protocol. WLAN manufacturers can circumvent this problem by incorporating the ability to generate random keys across the network and putting in place user requirements concerning the length and style of passwords.

Microsoft responded to this potential threat by providing a Windows XP download that alters the way the operating systems communicates with the Wi-Fi network – using separately generated keys for each system user rather than one, albeit encrypted, key for the network connection

Alter Sage asked:


Global roaming services have begun to revolutionise business processes with major increases in Wi-Fi hotspots and 3G global connectivity. Not surprisingly, the use of Wi-Fi and mobile 3G for internet access has grown steadily over the past few years, especially for business users. Increased connectivity means that businesses are no longer disadvantaged by being disconnected when out of the office. With Wi-Fi and 3G technology, employees are able to remain connected to their business at all times, no matter what their location. This ultimately saves money whilst allowing business users access to advanced features of the latest internet technology.

The upsurge of web users switching to global roaming and 3G voice and data gateway services has been an increasing trend in business practice. Smartphones, business travel, multiple branches and home access to work servers have become commonplace in most businesses and require dependable technology for smooth productivity.

Global Roaming for Business

Many companies require employees to travel on international business trips and rely on Wi-Fi hotspots for internet access. VoIP carrier services, advanced user features, smartphone technology and dependable services allow for optimum communication anywhere on the globe, charged at local rates.

The amount of time spent by employees working out of office has also increased, placing a greater demand upon Wi-Fi and 3G mobile technology. VoIP functions are supported by Wi-Fi and 3G, meaning that employees who are away from the office network are still able to access all VoIP features. This includes free calls between VoIP users and reduced calls to other sites, no line rental or heavy maintenance costs, voicemail, email, fax and complete control over call settings. The hosted VoIP telephone solution has helped to revolutionise business processes, allowing for better service production and business productivity.

Growing numbers of Wi-Fi hotspots

According to a study commissioned by a major provider of remote and mobile connectivity devices, the worldwide use of Wi-Fi hotspots has increased by 46% whilst the use of 3G data grew by 59% in 2008. The use of Wi-Fi technology in public locations tripled between 2007 and 2008. Europe overtook the US in terms of Wi-Fi usage. Europe, Asia, the Pacific and Latin America saw steep rises in Wi-Fi use, especially in locations associated with commuting such as hotels, restaurants, airports and train stations. Three quarters of Wi-Fi sessions were recorded as taking place in aeroplanes, hotels and stations and other locations connected to inter-city travel.

3G mobile connectivity

Mobile and laptop users require global roaming services which are economical, user friendly and secure. 3G technology has begun to provide the necessary services and its popularity has grown as a result, especially in the US which experienced the highest increase from 2007 to 2008 which saw the use of 3G for business grow 59%.

Smartphones outwit costly mobile rates

Another important consideration is the introduction and increasing use of smartphones for business and personal use. Handsets like Blackberry and the iPhone rely on 3G technology and Wi-Fi functionality as heavily as laptops do, and with the increase in use of smartphones worldwide, an increase in 3G and Wi-Fi use is inevitable.

iPhone sales sky-rocketed by 123% in the first quarter of 2009 despite the financial difficulties caused by the current recession. The number of people able to make use of 3G technology and carrier services has risen from 35% to 53%. Mobile 3G has increased by 59% from 2007 to 2008 with mobile phones using an average data amount of 211MB per month.

Whilst 3G is popular for smartphones, most have Wi-Fi functionality coupled with Bluetooth technology and 3G.  The increasing occurrence of dual support for 3G cellular networks and Wi-Fi hotspots has the possibility of lowering costs. High mobile tariffs have been prohibitive for customers and Wi-Fi functionality on smartphones has the potential to stall these inflating costs.

Global roaming technology has become indispensable to the workforce, allowing employees to stay connected and communicate with ease. The large growth trends in use of Wi-Fi and 3G for global roaming and massive spike in smartphone sales illustrates that consumer confidence has increased. Web users expect good connectivity for optimum operational performance and according to the increasing levels of 3G and Wi-Fi use; this is an indication that global roaming is widely considered the best option for lower costs, secure access and strong connectivity.

Adam Caitlin asked:


Wi-fi phones are the best example of revolutionary change in the communication technology. In the fast growing generation, one wants almost everything at their doorstep and in a much sorted way. In fact this advanced technology allows the mobile user to access fast speed internet anywhere. One can get Wi-fi technology in laptops, desktop computers, electronic video game consoles, mobile phones, printers etc. In this modern world, one cannot imagine life without the mobile phones. The ultra next generation wants to carry smartphones which are embedded with upgraded advanced technology features.

The companies are working too hard in order to meet the requirements of the 21st century generation. The market is hoarded up with variety of best Wi-fi phones which can create turmoil among the mobile users. Now-a-days almost every company is designing the mobile phones which supports this Wireless fidelity technology. This advanced technology works on signals which actually transfer the data at much fast speed. Moreover, with the help of this upgraded technology the mobile user can interact with loved ones in any region even while traveling.

This advanced technology is very popular among the every age group. It is admired by almost every individual across the globe. There is great demand of these wireless fidelity mobile phones. Such set of handsets allows users to communicate with others via VoIP. Apart from all, with this latest technology the mobile user can interact with others through video calling and voice dialling. The Wi-fi technology smartphones support high speed data processing. With this amazing mobile technology, an individual can surf high speed internet. In the meanwhile the user can access various social networking websites like Orkut, Myspace, Facebook etc. This improved wireless fidelity technology works on signals. Moreover, the Wi-Fi smartphones support various third generation technologies like HSDPA, EDGE, GPRS that allow user to transfer the data at faster speed and hence provide better connectivity. These hi-tech handsets supports various multimedia messaging features. An individual can share picture or videos among friends via MMS. With this technology the mobile users can create, send and receive important emails with attachments through their gizmo. It is very useful for both professional works as well as personal use.

This type of hi-tech handsets are best for the users which need to travel a lot. In fact the mobile arena is flourished with wide range of the best Wifi phones. These smartphones include sophisticated features and allows users to experience high speed web browsing. Such handsets have the potential to create anxiety among the mobile users. These gadgets by using VoIP convert the voice into data which can be easily transferred to other users at faster speed.

Chandan asked:


Wi-Fi or wireless fidelity is the term commonly present in today’s life of WWW. WWW or World Wide Web is the factor behind today’s fast moving life. And this advancing factor is again advanced by the invention of Wi-Fi Hotspot software technology, the wireless way of connecting worldwide. The Wi-Fi use in the networks is growing three folded. All the companies are moving towards this option of hotspot software to make use of the best available technique in the market. But the growing use of Hotspot Wireless network increases potential risks of the security for the organization and also for each and every user. And a wireless network is much easier than a cabled one to intrude for the hackers. So, here proper security measures are strictly required.

But whatever the threat it bears it just is an added advantage into our life style. Hotspot software can make your life happier. Let us start simply with the remote control you have for your TV set. It is just there to lessen your work and to give you an immediate satisfaction. Similarly there are Bluetooth technologies widely available in almost all the mobile sets. They are also there playing the big role in making life easier with connectivity. So, hotspot software is also performing the same task in lessening your work and satisfying you more while you connect to the world. Hotspot software, the Wi-Fi technology changes the life styles of every user. It comes with a wireless option that was not available earlier with your wired desktop. Now you have those laptops and PDAs with inbuilt Wi-Fi hotspot software based technologies and your life has got the ease of cable less connectivity. Along with this you have got the ease of mobility. You can move anywhere around the world and you just need a Wi-Fi using place to get connected, that’s all. This absolute freedom of mobility is an important contribution of Wi-Fi hotspot software technology. Now you can relax at your office cafeteria and at the same time answer to those messenger chat lines from your client. So, mobility is the factor added to your life style by the use of Wi-Fi technology. The next big factor adding to your life style is the simplicity attached to the use of Wi-Fi; it is because connecting via Wi-Fi is a single touch option. You can connect to internet with this hotspot software technology with just a single button touch or mouse click.

Adding style to your lifestyle is another good factor accompanying the use of Wi-Fi technology. If you are using this hotspot software technology then you should be sure that you are going with the current trend in the technological field. Being with the latest trend is the ultimate style statement showing how updated you are. Apart from that it represents the techno savvy part of your life style. If you are using the most updated technology, you are supposed to be a techno savvy guy irrespective of the fact that you need to take the help of your office networking guy every time you try to connect.

So, with the use of this hotspot software technology, the Wi-Fi technology you can have an advanced life style which is fast yet hassle free. What else than a lifestyle of this ease you need! Just go on and connect via Wi-Fi hotspot software technology.

Sarah Jones19 asked:


The growth of Wi- Fi technology has spanned global boundaries and emerged as one of the most effective tools for communication. The solution to be offered by Bandspeed  will be an integration of signal analyzer IC, firmware, user application monitoring and radio frequency.

When you are looking for top quality  Wi- Fi Support on any of your system, this technology will keep you miles ahead. The network performance of your systems will increase if you decide to take the help of this technological aid. When this system is implemented, the devices will be able to adjust automatically with the various configurations. The network can be easily connected to WAN access points, LAN access points, laptops, computers, RF sensors and broadband gateways.

If we delve into the history of wireless communications and Internet Set up, it is quite susceptible to radio frequencies from variable sources. The WLans with 802.11 configuration provides frequency interventions to any device in the signal ranging from wireless video cameras, cordless phones or microwave ovens.

The Wi- Fi Support system developed by Bandspeed emphasizes that the analyzer is fully capable of hooking on to a networking equipment. The AirMaestro Embedded Signal Analyzer scans all IEEE 802.11 channels in the 2.4 GHz and 5 GHz Wi-Fi frequency bands. The total range of interferers can also be detected and classified by it.



If you are owning a small business, the analyzer can help you immensely as the price offered is quite affordable. Each 3100AG access is offered with the configuration of 3 802.11a/g radios. As a customer you can advertise in the network which constitutes 2.4 and %GHz bands. The third radio which is available scans both the bands and provides spectrum analysis on the spot.  The complete price of the analyzer from Bandspeed is available at a price of 15$. The system has been intricately designed for a flawless application in OED/OEM stacks. As a user you can visualize the RF environment in various ways like dynamic channel management displays, advanced spectrum analysis and time slots utilization. For the overall function of the system, a mechanism called Automated and Intelligent Channel Selection algorithm is followed. The Air Maestro Spectrum Analysis Solution will work wonders for Wi- Fi Support technology and provide uninterrupted connectivity.

Jaya Sinha asked:


ess landscape in India

Several novel technologies are coming up to explore wireless Local Area Network. The growth of wireless LAN is flourishing at the marvelous pace. The Wi-Fi is becoming a necessity for the incentive and complex implementation in enterprises. The technology offers the basic benefits to an industry like

•    Reduction in cost,

•    Improved performance,

•    Easy management,

•    Ease to add more users to the network,

•    Greater security etc.

The Indian Wireless LAN market has still not perched flags high. But, according to recent reports it is crawling well now a days and slowly it will show improvements. The market for the wireless products and applications is estimated to be approximately $120 million and 50 million for the wireless network gear alone for the year 2008 and is expected to grow at much faster rate of 70% in the coming years.

Gigantic companies like HP, ProCurve, Wipro etc, are shifting towards mobility. These companies have to carefully make a few considerations before going wireless. The first issue related to the well being of the industry is security. In WLAN the access is not limited to selective number of users. Now, it goes to unlimited number of users and as a result it becomes easy for the intruders to breach the security of the network.

Wireless network sometimes affects the quality of the data transfer. Because the interference enhances with distance that ultimately affects the quality of data transfer.

Another factor that affects the well being of wireless network is manageability. It is not an uncomplicated task to manage a wireless network, make alterations and troubleshoot the network problems with complex configuration.

The wireless networking is a big challenge as some external factors also affect its performance like the battery life of mobile devices, whether conditions and usage of licensed network.  The Indian market is dealing with all these issues and still constructing its way by breaking stones of obstacles.

With market growth and major enhancements happening in Wi-Fi space, future seems to be very bright. One of the major turning points has been the launch of 802.11n. According to recent market reports, In India, at present the 802.11g networking standard is common among big enterprises, the next eagerly awaited standard 802.11n is expected to make its way which will improve access speed and quality of data transfer. Conceptually, it offers six times the speed and less than three times the price along with longer distance coverage. Products based upon the new standard are likely to hit the market in 2009. Organizations are looking forward to welcome the new products.

The wireless network is implemented by National informatics Center (NIC), India. It is a premier Information Technology organization that provides IT solutions to the Government of India. NIC has set up a satellite-based nationwide computer communications network called NICNET. It has connected 1,400 nodes, connecting the national capital, state capitals and the district headquarters to one another.

Another implementation is done by Cisco; the company targets all the verticals along with end-users, home users and retail through Linksys.

Nash asked:


o doubt that in the age of wireless, Wi-Fi is a trademark of the Wi-Fi Alliance for certified products based on the IEEE 802.11 standards. This certification warrants interoperability between different wireless devices. The wifi cell phones let people make connections using a local wireless Internet access point and seamlessly switch over to a cell phone network whenever necessary. The net result is greater flexibility in mobile communications as well as potential cost savings gained by shifting call minutes that would otherwise count against a cell phone plan onto the Internet.

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The Newest Wi-Fi phone from quality China phone manufacturers here! A Phone with WiFI is capable of connecting to INTERNET using WIFI Hot-Spots found in many places. Save money using WIFI mobile phone! So, get up and choose the best phone for yourself and add more value and fun to your life.

Darlene Kaitlene asked:


In a shrinking world (thanks to technological advancements), it is suicidal to stay ensconced into one’s own world and not venture out to lands of immense possibilities. The mantra for today is think global! But how can you think global if you can not communicate freely with the world outside? It is difficult.

Well, technological advancement is the cause and consequence of the need for smooth communication. And that is the reason – today we have VoIP solution like NETGEAR SPH101VOIP Skype Wi-Fi Phones. NETGEAR SPH101VOIP Skype Wi-Fi Phone is a wireless mobile phone which enables you to make free internet calls to those who have Skype or Wi-Fi wireless Internet connection.

You can make calls with NETGEAR’s SPH101VOIP Skype Wi-Fi Phone without the requirement of a desktop or laptop. All you need is a Wi-Fi network around you so that you are online. Just like you do with a PC, you can also make free calls to Skype users around the world at any time.

The NETGEAR’s SPH101VOIP Skype Wi-Fi Phone has colour display quite similar to your laptop. The screen will show all your friends who are online. This way you are always connected to your friends, colleagues and clients whether or not you are near your PC.

Apart from calls to other Skype numbers, you can also make calls to any phone in any part of the world for just a few pennies per minute. And what more, you do not have to pay any other monthly fees apart from the Skype Call charges. Besides this, you can forward your calls to your mobile, land-line or to another Skype ID.

NETGEAR SPH101VOIP Skype Wi-Fi Phones are ideal both for your work and for your fun times. You can do all that you can do with your Skype id on this phone. This is a cool VoIP solution, which is available with leading online web stores.