Definition - What does Nomadic Computing mean? Nomadic computing is the use of mobile computing technology to connect to the global Internet or use specific data resources from a stored location while moving around from one place to another. The phenomenon of nomadic computing relies on a number of key innovations that have allowed people around the world to access shared resources from nearly anywhere. These include the emergence of the global Internet as well as advances in storage media, server design, and encryption and security protocols for remote access. Nomadic computing is also known as mobile computing. Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams. x-tics of mobile computing devices Portability: Facilitates movement of device(s) within the mobile computing environment. Connectivity: Ability to continuously stay connected with minimal amount of lag/downtime, without being affected by movements of the connected nodes Social Interactivity: Maintaining the connectivity to collaborate with other users, at least within the same environment. Individuality: Adapting the technology to suit individual needs. Limitations Expandability and Replaceability: In contrast to the common traditional motherboard-based PC the SoC architecture in which they are embedded makes impossible these features. Lack of a BIOS: As most smart devices lack of a proper BIOS they're bootloading capabilities are limited, as they can only boot into the single operative system with which it came, in contrast with the PC BIOS model. Range and bandwidth: Mobile Internet access is generally slower than direct cable connections, using technologies such as GPRS and EDGE, and more recently HSDPA, HSUPA, 3G and 4G networks and also the proposed 5G network. These networks are usually available within range of commercial cell phone towers. High speed network wireless LANs are inexpensive but have very limited range. Security standards: When working mobile, one is dependent on public networks, requiring careful use of VPN. Security is a major concern while concerning the mobile computing standards on the fleet. One can easily attack the VPN through a huge number of networks interconnected through the line. Power consumption: When a power outlet or portable generator is not available, mobile computers must rely entirely on battery power. Combined with the compact size of many mobile devices, this often means unusually expensive batteries must be used to obtain the necessary battery life. Transmission interferences: Weather, terrain, and the range from the nearest signal point can all interfere with signal reception. Reception in tunnels, some buildings, and rural areas is often poor. Potential health hazards: People who use mobile devices while driving are often distracted from driving and are thus assumed more likely to be involved in traffic accidents. (While this may seem obvious, there is considerable discussion about whether banning mobile device use while driving reduces accidents or not.) Cell phones may interfere with sensitive medical devices. Questions concerning mobile phone radiation and health have been raised. Human interface with device: Screens and keyboards tend to be small, which may make them hard to use. Alternate input methods such as speech or handwriting recognition require training. Advantages & Disadvantages of a Mobile IP Uniqueness A mobile IP address allows users to connect to the Internet without a normal static or dynamic IP address through the use of a unique mobile IP address. This unique address lets the computer connect through a network to a home IP address but still utilize and communicate with the network's protocol. Having a unique IP is important for routing information to the correct computer. In short, if it were not for mobile IPs, information would continue to be routed to the last known IP address at which that computer was located, and a seamless connection would be impossible. Portability IP creation on the go is the only way that users can access the Internet while away from a traditional modem/router setup. Mobile IP addresses create a tunnel to a host server, which allows an access point to the Internet from any location where a signal can be received. Mobile IPs can create connection protocols to connect to the Internet through multiple servers and networks. A mobile IP address allows users to roam through multiple networks and maintain an IP address. This option is useful for employees who travel throughout a building and cross into multiple wireless zones. Spotty Internet Availability Spotty Internet availability is still something that plagues mobile users. A mobile IP requires a strong signal to connect to the Internet. In major metropolises, signals are easily obtained, and a mobile IP will be able to roam between networks with little problem at all. In many urban areas, however, coverage is still sparse, and strong signals are difficult to come by. In general, the stronger the signal, the faster and more reliable the connection will be. In the case of a weak signal, it is typical for the connection to be slow and unstable. VoIP (Voice over Internet Protocol) is simply the transmission of voice traffic over IP-based networks . The Internet Protocol (IP) was originally designed for data networking. The success of IP in becoming a world standard for data networking has led to its adaptation to voice networking. Some background history: Although VoIP has been creating quite a stir in the press recently, it’s actually not a new idea at all. VoIP has been around in one form or another since 1973 when it began as an experiment by the US Department of Defense. Why VoIP is better ? VoIP has become popular largely because of the cost advantages to consumers over traditional telepone networks. VoIP slashes your monthly phone bill by a whopping fifty percent. Let's put some light over these claims. It offers cheaper international long distance rates which are generally one-tenth of what is charged by traditional phone companies. Its portability makes it a very good option and one could avoid expensive hotel phone charges and cell phone roaming charges. What one requires is just a high speed connection where one could plug the adapter into and people could reach you at your local number irrespective of your location. Most Internet connections are charged using a flat monthly fee structure. Using the Internet connection for both data traffic and voice calls can allow consumers to get rid of one monthly payment. In addition, VoIP plans do not charge a per-minute fee for long distance. By making VoIP calls using internet enabled cell phones one could avoid wireless roaming fees and long distance rates which generally touch north. Most of the times in-network calls to other VoIP service subscribers are free even if the calling parties are located in different parts of the world. How does it work? Just to confuse people, there are many kinds of VoIP. Using voice chat in MSN , G Talk or Yahoo messenger could be regarded as VoIP, so could the highly publicised Skype; but these are all proprietary systems. To talk to someone using MSN, the person at the other end also needs MSN. The same applies to Yahoo and, to a great extent, to Skype. They use their own special system that isn't open and won't connect to other systems easily. True VoIP should really be based on the SIP system which is the recognized standard. Any SIP compatible device can talk to any other; you don't even use a PC. Any SIP telephone can call another right over the internet, you don't need any additional equipment or even a phone provider. Just plug your SIP phone into the internet connection, configure it and then dial the other person right over the internet. In all VoIP systems, your voice is converted into packets of data, like little files, and then transmitted to the recipient over the internet and decoded back into your voice at the other end. To make it quicker, these packets are compressed before transmission, a bit like zipping a file. Advantages of VoIP: VoIP phone service providers offer many advantages to the residential and small office/home office user. If you have a high speed internet connection then choosing a VoIP phone service might be right for you. Low Cost : This technology leads to greater financial savings. This happens because there exists only one network carrying the voice and data provided by only one supplier. If you have a broadband Internet connection (DSL or cable), you can make PC-to-PC phone calls anywhere in the world for free. If you wish to make a PC-to-phone connection, there's usually a charge for this but probably much cheaper than your regular phone service. You can pay as you go or you can sign up with a VOIP service provider and pay a monthly fee in return for unlimited calls within a certain geographic area. For example, some VOIP services in the United States allow you to call anywhere in North America at no extra charge. Low Taxes : Since the calls are being carried over the Internet, governments have not heavily taxed VoIP phone services. Compare that to your local telephone bill (go ahead and take a close look) and you will see you are spending quite a bit on taxes each month. Therefore, choosing a VoIP provider could add up to significant savings for you and your family. Portability : One important concept to understand about VoIP is that unlike it’s forefathers (let’s call them PSTN for now), it is not distance or location dependent. As far as VoIP is concerned, you could be calling your supplier 1,000 miles away in Indonesia or calling your business partner on the other end of town, and it doesn’t make any difference at all, in terms of connectivity and cost. You can make and receive phone calls wherever there is a broadband connection simply by signing in to your VoIP account. This makes VoIP as convenient as e-mail – if you are traveling, simply pack a headset or Internet phone and you can talk to your family or business associates for almost nothing. No extra cables, no extra cost : A VoIP phone number, unlike your regular phone number, is completely portable. Most commonly referred to as a virtual number, you can take it with you anywhere you go. Even if you change your office address to another state, you phone number can go with you. Heck, you can even take your whole business with you wherever you travel. Features : Unlike regular phone service which usually charges more for extra features, VOIP comes with a host of advanced communication features. For example, call forwarding, call waiting, voicemail, caller ID and three-way calling are some of the many services included with VOIP telephone service at no extra charge. You can also send data such as pictures and documents at the same time you are talking on the phone. VoIP phones can integrate with other services available over the Internet, including video conversation, message or data file exchange in parallel with the conversation, audio conferencing, managing address books and passing information about whether others (e.g. friends or colleagues) are available online to interested parties. Flexibility : When you choose a VoIP phone service provider, you will be sent a converter to allow a regular phone to use the VoIP phone service. Your phone number is programmed into the converter. This means that you can take your phone converter and phone number and use them wherever you travel in the world, just as long as you have access to a high-speed Internet connection. Because your telephone number is based in your converter (and not your home/office), you have the option of choosing any area code for your phone number. Some carriers will allow you to have more than 1 phone number in different area codes for a small additional fee (called a virtual phone number). video-conferencing : VoIP enables advanced bandwidth capabilities and improved video-conferencing and at a reasonable price. Disadvantages of VoIP: If VOIP is starting to sound really good to you, make sure you understand the following downsides as well. No service during a power outage : During a blackout a regular phone is kept in service by the current supplied through the phone line. This is not possible with IP phones, so when the power goes out, there is no VOIP phone service. In order to use VoIP during a power outage, an uninterruptible power supply or a generator must be installed on the premises. It should be noted that many early adopters of VoIP are also users of other phone equipment such as PBX and cordless phone bases that also rely on power not provided by the telephone company. Emergency calls : Another major concern with VOIP involves emergency 911 calls. Traditional phone equipment can trace your location. Emergency calls are diverted to the nearest call center where the operator can see your location in case you can't talk. However, because a voice-over-IP call is essentially a transfer of data between two IP addresses, not physical addresses, with VOIP there is currently no way to determine where your VOIP phone call is originating from. Although many companies are making an effort to provide for emergency calls in their service, this issue remains an important deterrent against VoIP. Reliability : Because VOIP relies on an Internet connection, your VOIP service will be affected by the quality and reliability of your broadband Internet service and sometimes by the limitations of your PC. Poor Internet connections and congestion can result in garbled or distorted voice quality. If you are using your computer at the same time as making a computer VOIP call, you may find that voice quality deteriorates dramatically. This is more noticeable in highly congested networks and/or where there are long distances and/or internetworking between end points. VoIP Voice Quality : VoIP has a bit to improve on Voice Quality, but not in all cases. VoIP QoS(Quality of service) depends on so many factors: your broadband connection, your hardware, the service provided by your provider, the destination of your call etc. More and more people are enjoying high quality of phone calls using VoIP, but still many users complain of hearing Martian, having to wait a lot before hearing an answer etc. Security : This one is the last in this list, but it is not the least! Security is a main concern with VoIP, as it is with other Internet technologies. The most prominent security issues over VoIP are identity and service theft, viruses and malware, denial of service, spamming, call tampering and phishing attacks.