Mobile multimedia architectures

Mobile and wireless Internet systems have brought in several advantages. People in business are benefited by Wi-Fi as they travel around for their business purposes. Furthermore, even if you do not have your laptop with you, your mobile would connect you to Wi-Fi and you would never miss your important emails as they drop into your email inbox. Wi-Fi also helps you to set up wireless internet connectivity at home. If there is more than one user, Wi-Fi connects all your computers to the Internet, and sets up computer to computer connectivity as well. Wireless network brings in sheer mobility, and it also provides rigidity, and helps you to reach out to distant places.

With the progress of technology and availability of bandwidth, Wi-Fi connectivity prices have dropped to a level where all the modern devices such as, mobile phones, laptops, personal digital assistants, iPhones, iPods etc. can now all access the Internet without any hassle. Wireless and mobile network provide the user with a better security than a satellite network, since, the signal as in a satellite network, does not travel as it is in the process of transfer. In case of wireless network the signal travels straight to the recipient. Wireless networking has made faster downloads possible, and as far as applications are concerned, such as, games, audio-video programs, chats, multimember chats, video-conference calls, navigation has become easier, making your computer more efficient.

When you set up a wireless network, you would be able to access Internet within a radius of 100 feet. This allows you the mobility, where you can move about in your office and access the Internet or your emails from either your laptop or WAP enabled mobile phone. Your personal computers, laptops are all already installed with wireless chipsets which allow you to connect to the Internet automatically. The Bluetooth in your mobile works on wireless connectivity, making your life easier with a wide range of new and advanced wireless gadgets, such as, wireless microphones, wireless headsets, wireless stereo speakers, computer peripherals, televisions.

Architecture:

With the advent of wireless connectivity, it has become an important tool in business and profession, making wireless networking a valuable asset for the modern world. WAN, which is the term used for Wireless local area networking, is a radio technology which provides super speed, unlike the cellular technology. The state-of-art technology standard, IEEE 802.11b offers a maximum speed of up to 11 Mbps. However, for a single user the technology provides a maximum through-put of 11 Mbps, in an average of 6.5 Mbps, while General Packet Radio (GPRS) provides a data rate of 172 kbps, typically 42 kbps, and the third-generation terminal offering to 2 Mbps, typically 144 kbps.

The wireless network and the Internet have started to converge globally. Worldwide Internet users have grown from 200 million to over 3 billion by the year 2008, and it is expected that during the same time wireless network users would grow by leaps and bounds from 300 million to over 2 billion. The market dynamics is now driving the business industries in the world towards packet based IP technology, which provides a new one-of-its-kind opportunity to the operators in providing variety of new customised services to mobile cellular subscribers.

The next generation will see the wireless packet based networking, which will be flexible in architecture, open, and standard based. The next generation of wireless network will facilitate easy migration from the present hierarchical circuit-switched technology to peer-to-peer packet-switched network. In the very near future wireless network would be able to take the true advantage of peer-to-peer networks and provide better facilities to the service providers.

Wi-Fi – IEEE 802.11 wireless LAN:

All the members of 802.11 family use over-the-air modulation that utilises the same basic protocol. Amongst the protocols, the ones defined by the 802.11b and 802.11g protocols are most popular, and these definitions are the ones which have been formed by changes made in the original ones. Though 802.11 was the first ever standard for wireless network, the protocol 802.11b was the first one which has been widely accepted. This acceptance is followed by the ones defined by 802.11g and 802.11n, where 802.11n is the new multi-streaming protocol and is still under a draft form.

The WLAN standard, IEEE 802.11, has a wide acceptance for several different environments existing today. The simplicity and rigidness of this technology are the two main characteristics which prove to be fail-proof due the distributed approach. IEEE 802.11 uses ISM band at 2.4 GHz, and it produces a data rate which can go upto 11 Mbps at wireless medium.

A higher data rate is achieved by the new version IEEE 802.11a with a through-put of 54 Mbps at the wireless medium by using the ODFM modulation technique. Quite recently the group, looking after IEEE 802.11, has managed to enhance the current 802.11 MAC protocol which supports applications with QoS (quality of Service) requirements. Efforts are on to standardise the enhancement of QoS functionality of WANs, which could bring about several opportunities for new multimedia applications in mobile and other portable devices. Easy buying with payday advance

Optical networks and DWDM

Businesses depend upon their networks as the lifeblood of day-to-day operations. Bottlenecks in data communication mean lost time and lost time translates to a loss in revenue. It is essential for companies to stay up to date with the best technologies that keep the network performing at an optimum level.

Information sharing has permeated society at every level, simultaneously straining the backbones on which the global network was built. Understanding the latest innovations is key for any business looking to accelerate past the competition.

The explosive growth of voice and data transmission flowing over the Internet Protocol (IP) has been largely responsible for straining back-haul network bandwidth. Some ISPs are reporting that bandwidth demand on their backbone connections is doubling approximately every 8 to 14 months in response to ever-increasing Internet traffic.

The Internet backbone must further deal with the increasingly complex makeup of the traffic itself. Multiple data protocols must be transmitted, including circuit-based communications such as fax or TDM voice, IP packets or even packet-switching protocols and frame relay.

Faced with these concerns, Internet carriers traditionally were forced to lay additional fiber optic cabling to accommodate additional demand for bandwidth. However, at a minimum starting cost of $70,000 USD per mile, the associated costs are prohibitive in most situations except for the highest-level backbone connections.

Need always leads to innovation. The development of DWDM (Dense Wavelength Division Multiplexing) is a key innovation that allows for more bandwidth without installing additional, cost-prohibitive cabling. The concept is easy to understand: Increase the number of wavelengths that can be transmitted on a fiber. Fiber optic cabling uses lasers for transmission through the glass medium.

Previously, these transmissions were carried out at a single frequency. By simultaneously transmitting data at different frequencies or different light colors, the signal is multiplexed. This action effectively increases fiber optic cable capacity by a factor between 16 and 32.

Since the introduction of fiber optic cabling, SONET (Synchronous Optical Network) has been the standard communication protocol in North America. SONET works by taking network signals and multiplexing them into a single wavelength to be transmitted over fiber. Counting on a single light wave to carry all the data drastically limits the capacity of the protocol.

SONET transports TDM data over the optical medium. Further inefficiency is created by current TDM (Time Division Multiplexing) technology. TDM was initially developed by phone companies to maximize the amount of voice data that can be transmitted over a medium.

TDM works by increasing capacity of the backbone link by collecting bits of raw data from multiple sources and multiplexing them at the higher transmission rate. TDM reserves time slots in the process to transmit the multiple sources in round-robin order. However, the proliferation of other data formats not based on circuits such as IP and cell-based transmissions forces TDM to deal with formats for which it was not designed. For example, Ethernet transmissions over SONET result in wasted bandwidth of up to 80% in a 10 Base-T connection.

TDM was never designed to handle anything other than voice data. Where SONET relies on TDM to transmit data for which it was not designed, drastic deficiencies occur.

Here are some key benefits of DWDM technology over SONET:

• Transparency – Operating at the primary layer of network architecture with raw data bits and streams, DWDM is able to support TDM and any other data format such as Ethernet, ATM, Fibre Channel or ESCON.

• Scalability – DWDM utilizes “dark fiber” or bandwidth otherwise wasted by inefficient transmission protocols like SONET for an instant boost.

• Dynamic provisioning – Eliminating time slots for data transmission allows for connections to be provided dynamically at a much higher rate. • Reduced need for regenerators – Transmitting multiple signals over a single fiber decreases the need for additional expensive equipment otherwise needed to re-amplify and de-multiplex signals over multiple fibers.

Four important questions readers should ask themselves:

1. Are you experiencing bottlenecks in your fiber optic network?

2. Does your network continuously transmit multiple data formats?

3. Are you looking for a simple, yet highly effective technology to gain a competitive edge?

4. What is keeping your business from transitioning to DWDM on the back-haul networks across the enterprise? DWDM technology dramatically increases transmission capacity while simplifying scalability concerns at the same time. The primary requirement is installing higher transmission capacity at one end of the fiber optic cabling.

DWDM drastically reduces signal congestion created by amplifiers and regenerators. High-capacity network transmissions around the business can be conducted without some of this equipment when DWDM is implemented.

DWDM is a smart strategy for a highly optimized optical network. Since the sharing of information is the lifeblood of any business, the network must have the highest level of availability, and downtime must be kept to an absolute minimum.

Backups performed in real-time and decentralized processing are essential to keeping mission-critical applications online, as are parallel processing and a comprehensive disaster recovery plan. The common theme among these best practices is the requirement for a network of the highest quality, efficiency and reliability.

Dense Wavelength Division Multiplexing is a smart alternative to traditional Time Division Multiplexing. Know what your options are now and consider the benefits as you expand business operations.

Personal Area Networks

Personal Area Networks (PAN) are formed by wireless communications between devices by way of technologies such as Bluetooth and UWB. PAN standards are embodied by the IEEE 802.15 family of “Home Wireless” standards, which superseded older infrared standards and HomeRF for dominance in this area of wireless communications

Like all personalization technologies, PAN applications are virtually limitless. However, a key capability for a PAN is to enable devices to autonomously detect and acquire one another. This provides the ability for personalization through unconscious communications. For example, a PAN in ones automobile would provide various telematics applications, such as the ability for the system to detect the presence of the user, thereby allowing the mobile handset to automatically acquire pertinent information for driving such as weather and road conditions.

One of the fundamental advantages of PANs is that they negate the need for wires, allowing the user to, for example, have a wireless headset, create ad hoc connections to

Other applications include mobile commerce in which user of a mobile device communicates with another machine for commerce such as ticket purchase, vending and other small purchases.

The evolution of PANs will be from man-to-man, man-to-machine, and finally machine-to-machine.

Issues and Challenges with PANs

The biggest initial issue will simply be to equip devices with software to enable the PAN connection. This will occur once technology such as Bluetooth is cost effective and available in large quantities for deployment.

One of the biggest issues with PANs is the ability for devices to inter-operate with one another. This is not so much an issue with pre-established networks of devices, which all have the same vendor equipment, but it is a major issue for inter-vendor equipment connections. This is a major factor for unconscious communications. Companies are working to solve these issues with various equipment mediation and interoperability software.

Ad hoc vs. Unconscious Communications

Ad hoc connections are simply those that occur in an automatic fashion, but the user is engaged in some activity in which it is known that a connection is about to occur. Examples include connecting to a LAN or buying a beverage from a vending machine.

On the other hand, unconscious communications occur as a result of automatic connections that made between devices unbeknownst to the user. Examples include a user coming home and the local base station in the home sensing this event and thus messaging to the network to treat all calls as home zone calls rather than mobile calls in the macro network. Unconscious connections are the real end-goal for many applications that involve personalization and mobile commerce. The real issue will be to solve the interoperability problems between differing vendor provided equipment.

PAN Standards

  • 802.15.1a: Bluetooth (2.4GHz at 1Mbps)
  • 802.15.2: Coexistence of PANs with one another
  • 802.15.3: High rate PAN (2.4GHz at 55 Mbps)
  • 802.15.3a: Alternative high rate PAN for UWB (2.4GHz at 110 Mbps)
  • 802.15.4: Low rate PAN – Zigbee
  • 802.15.4a: Alternative low rate – low power UWB
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