The Key to Happiness

This evening while driving back home to Girinagar from Pune, I tuned in to Radio City and there was a programme called Return Ticket and I was delighted to hear a great selection of melodious old hindi film songs of Rafi, Lata, Asha, Mukesh and Kishore.

I felt happy, very happy.

Just hearing good music can make you happy.

Small things can make you happy, as long as you keep your threshold of happiness low.

Yes, the key to happiness is keeping your pleasures mild.

COGNITIVE RADIO - a smart communication concept

COGNITIVE RADIO

[Here is an article on Cognitive Radio compiled by my students Shijesh, Sibil, Shyju and John by browsing the internet, books and journals]


The Radio Spectrum – that segment of the electromagnetic continuum comprising the radio-frequency range – accommodates myriad communications devices today.

As the Radio Spectrum gets is gets more and more crowded and available frequencies become scarce the evolution of Cognitive Radio may be able to optimally manage the available spectrum.

The use of radio frequency bands has been regulated in most countries through the process of spectrum allocation in which the use of a particular frequency band is restricted to the license holders of the band. Within this framework, spectrum has often been viewed as a scarce resource in high demand. However, various studies carried out have suggested that most licensed spectrums are often under-utilized with large spectral holes at different places at different times.

Cognitive Radio (CR) systems have been proposed as a possible solution to the spectrum crisis. The idea is to detect times when a specific licensed band is not used at a particular place and use that band for transmission without causing any significant interference to the transmissions of the license holder.

Built on the foundation of the Software Defined Radio (SDR), Cognitive Radios will learn and autonomously perform “cognitive” functions as a form of intelligence that comes from their ability to be defined and upgraded using software.

To examine the concept of cognitive radio consider the example.

Let’s say you walk into an empty café called Spectrum. Since all of the tables are available, you position yourself at the best one and settle down for a meal. [Let’s assume all tables have four seats and you occupy one seat].

A few minutes later, another person comes in and sits on a seat at another vacant table.

Soon, if all the tables are full [but there are a few vacant seats on some tables], a new patron must negotiate with someone already at a table to be allowed to share the table. [Maybe she may request you to let her occupy the vacant chair at your table, and you may agree].

This process of negotiation is the concept behind a technology called Cognitive Radio, a way to share and optimally utilize unused spectrum. Cognitive Radio is sometimes called Smart Radio because it senses its environment and reacts to it.

The present paucity of radio spectrum is primarily due to the cost and performance limits of legacy hardware established during the past century. Traditionally, radios were hardwired to operate at a particular power and frequency, and once a station was assigned a frequency, no other station could use it. Over the years, as engineers built radios in cheaper and smaller packages, it became possible to build intelligence into them, making the idea of sharing frequencies possible.

Engineers are now working to bring flexible operating intelligence to future radios, cell phones and other wireless communications devices. During the coming decade, cognitive radio technology should enable nearly any wireless system to locate and link to any locally available unused radio spectrum to best serve the consumer. Employing adaptive software, these smart devices could reconfigure their communications functions to meet the demands of the transmission network or the user.

Cognitive Radio will intelligently know, by sensing, adapting and learning, what to do based on prior experiential knowledge, by building an internal database that defines how to best operate in different places and at specific times of day.

As Cognitive Radios send and receive signals, they will nimbly leap and bound in and out of free bands as required, avoiding those that are already in use. This lightning-fast channel jumping will permit cognitive radio systems to transmit voice and data streams at reasonable speeds.

This efficient use of existing Radio Frequency resources will alleviate spectrum-availability traffic jams and wireless communications may become far more dependable, convenient and, perhaps, considerably economical than it is today. Indeed, if Cognitive Radio technology progresses as its developers hope the airwaves will never be the same again.

SDR - Software Defined Radio

SOFTWARE DEFINED RADIO [SDR]

[Here is an article on SDR compiled by my students Shijesh, Sibil, Shyju and John by browsing the internet, books and journals]


The rapid growth of technology and changing trends in the Communication techniques has paved way for the introduction of many telecommunication devices, many of which are not feasible to modify cost effectively due to lack of flexibility in their implementation. Software Defined Radio (SDR) technology mitigates this problem by providing the flexibility through software.

Software-Defined Radio (SDR) is a rapidly evolving technology that is receiving enormous recognition and generating widespread interest in the telecommunication industry. Over the last few years, analog radio systems are being replaced by digital radio systems and programmable hardware modules are increasingly being used in digital radio systems at different functional levels. SDR technology aims to take advantage of these programmable hardware modules to build open-architecture based radio system software.

An SDR system is a radio communication system where components that have typically been implemented in hardware are instead implemented using software on embedded computing devices. In other words SDR is a Radio in which some or all of the physical layer functions are software defined.

A Radio is any kind of device that wirelessly transmits or receives signals in the radio frequency (RF) part of the electromagnetic spectrum to facilitate the transfer of information.

In today's world, radios exist in a multitude of items such as cell phones, computers, car door openers, vehicles, and televisions.

While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics are practical enabling many processes that were once only theoretically possible.

In the past, radio systems were designed to communicate using one or two waveforms [waveform here refers to any specific standard like Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA) or it can be as simple as Frequency or Amplitude Modulation (FM or AM)].

As a result, two groups of people with different types of traditional radio were not able to communicate due to incompatibility problems. The need to communicate with people using different types of equipment can only be solved using software programmable radios because of its flexible architecture.

Traditional hardware based radio devices limit cross-functionality and can only be modified through physical intervention. This results in higher production costs and minimal flexibility in supporting multiple waveform standards. By contrast, software defined radio technology provides an efficient and comparatively inexpensive solution to this problem, allowing multi-mode, multi-band and/or multi-functional wireless devices that can be enhanced using software upgrades.

The primary goal of SDR is to replace as many analog components and hardwired digital VLSI devices of the transceiver (radio) as possible with programmable devices.

Some of the advantages of SDR are:

Multifunctionality. The same piece of hardware i.e. the radio set can be used to transmit, receive and process different communication signals that adhere to different air interface standards. This can be done simply by reconfiguring the software.

Global Mobility. The same piece of hardware i.e. the radio set can be used in different parts of the world that endorse different air interface standards. This can again be done simply by reconfiguring the software.

Compactness and power efficient design. Unlike traditional non-SDR systems, which require multiple hardware sets for multi-functional communication, the same piece of SDR hardware can be reduced for such a purpose. This results in compact and power –efficient design, especially as the number of systems increases.

Ease of manufacture. A SDR comprises of fewer hardware parts than a traditional radio since most processing is done in software within a general-purpose microprocessors or special purpose microprocessors like the DSP, or in reconfigurable hardware including FPGAs. This eases the production cycle for the manufacturer with lesser parts to standardize and produce.

Ease of upgrades. Any service upgrade can be easily introduced through the release of new software versions without the expense of recalling or replacing the hardware units. A user can simply download the software off the internet and load it into the SDR.

The most significant asset of SDR is versatility. Wireless systems employ protocols that vary from one service to another. Even in the same type of service, for example wireless fax, the protocol often differs from country to country. A single SDR set with an all-inclusive software repertoire can be used in any mode, anywhere in the world. Changing the service type, the mode, and/or the modulation protocol involves simply selecting and launching the requisite program, and making sure the batteries are adequately charged if portable operation is contemplated.

The ultimate goal of SDR engineers is to provide a single radio transceiver capable of playing the roles of GSM phone, CDMA phone, Wimax terminal, wireless fax, wireless Web browser, Global Positioning System (GPS) unit, and other functions still in the realm of science fiction.

SDR - Software Defined Radio

SOFTWARE DEFINED RADIO [SDR]

[Here is an article on SDR compiled by my students Shijesh, Sibil, Shyju and John by browsing the internet, books and journals]


The rapid growth of technology and changing trends in the Communication techniques has paved way for the introduction of many telecommunication devices, many of which are not feasible to modify cost effectively due to lack of flexibility in their implementation. Software Defined Radio (SDR) technology mitigates this problem by providing the flexibility through software.

Software-Defined Radio (SDR) is a rapidly evolving technology that is receiving enormous recognition and generating widespread interest in the telecommunication industry. Over the last few years, analog radio systems are being replaced by digital radio systems and programmable hardware modules are increasingly being used in digital radio systems at different functional levels. SDR technology aims to take advantage of these programmable hardware modules to build open-architecture based radio system software.

An SDR system is a radio communication system where components that have typically been implemented in hardware are instead implemented using software on embedded computing devices. In other words SDR is a Radio in which some or all of the physical layer functions are software defined.

A Radio is any kind of device that wirelessly transmits or receives signals in the radio frequency (RF) part of the electromagnetic spectrum to facilitate the transfer of information.

In today's world, radios exist in a multitude of items such as cell phones, computers, car door openers, vehicles, and televisions.

While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics are practical enabling many processes that were once only theoretically possible.

In the past, radio systems were designed to communicate using one or two waveforms [waveform here refers to any specific standard like Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA) or it can be as simple as Frequency or Amplitude Modulation (FM or AM)].

As a result, two groups of people with different types of traditional radio were not able to communicate due to incompatibility problems. The need to communicate with people using different types of equipment can only be solved using software programmable radios because of its flexible architecture.

Traditional hardware based radio devices limit cross-functionality and can only be modified through physical intervention. This results in higher production costs and minimal flexibility in supporting multiple waveform standards. By contrast, software defined radio technology provides an efficient and comparatively inexpensive solution to this problem, allowing multi-mode, multi-band and/or multi-functional wireless devices that can be enhanced using software upgrades.

The primary goal of SDR is to replace as many analog components and hardwired digital VLSI devices of the transceiver (radio) as possible with programmable devices.
Some of the advantages of SDR are:

Multifunctionality. The same piece of hardware i.e. the radio set can be used to transmit, receive and process different communication signals that adhere to different air interface standards. This can be done simply by reconfiguring the software.

Global Mobility. The same piece of hardware i.e. the radio set can be used in different parts of the world that endorse different air interface standards. This can again be done simply by reconfiguring the software.

Compactness and power efficient design. Unlike traditional non-SDR systems, which require multiple hardware sets for multi-functional communication, the same piece of SDR hardware can be reduced for such a purpose. This results in compact and power –efficient design, especially as the number of systems increases.

Ease of manufacture. A SDR comprises of fewer hardware parts than a traditional radio since most processing is done in software within a general-purpose microprocessors or special purpose microprocessors like the DSP, or in reconfigurable hardware including FPGAs. This eases the production cycle for the manufacturer with lesser parts to standardize and produce.

Ease of upgrades. Any service upgrade can be easily introduced through the release of new software versions without the expense of recalling or replacing the hardware units. A user can simply download the software off the internet and load it into the SDR.

The most significant asset of SDR is versatility. Wireless systems employ protocols that vary from one service to another. Even in the same type of service, for example wireless fax, the protocol often differs from country to country. A single SDR set with an all-inclusive software repertoire can be used in any mode, anywhere in the world. Changing the service type, the mode, and/or the modulation protocol involves simply selecting and launching the requisite program, and making sure the batteries are adequately charged if portable operation is contemplated.

The ultimate goal of SDR engineers is to provide a single radio transceiver capable of playing the roles of GSM phone, CDMA phone, Wimax terminal, wireless fax, wireless Web browser, Global Positioning System (GPS) unit, and other functions still in the realm of science fiction.

Cognitive Radio - The Future of Software Defined Radio

COGNITIVE RADIO

[Here is an article on Cognitive Radio compiled by my students Shijesh, Sibil, Shyju and John by browsing the internet, books and journals]


The Radio Spectrum – that segment of the electromagnetic continuum comprising the radio-frequency range – accommodates myriad communications devices today.

As the Radio Spectrum gets is gets more and more crowded and available frequencies become scarce the evolution of Cognitive Radio may be able to optimally manage the available spectrum.

The use of radio frequency bands has been regulated in most countries through the process of spectrum allocation in which the use of a particular frequency band is restricted to the license holders of the band. Within this framework, spectrum has often been viewed as a scarce resource in high demand. However, various studies carried out have suggested that most licensed spectrums are often under-utilized with large spectral holes at different places at different times.

Cognitive Radio (CR) systems have been proposed as a possible solution to the spectrum crisis. The idea is to detect times when a specific licensed band is not used at a particular place and use that band for transmission without causing any significant interference to the transmissions of the license holder. Built on the foundation of the Software Defined Radio (SDR), Cognitive Radios will learn and autonomously perform “cognitive” functions as a form of intelligence that comes from their ability to be defined and upgraded using software.

To examine the concept of cognitive radio consider the example.

Let’s say you walk into an empty café called Spectrum. Since all of the tables are available, you position yourself at the best one and settle down for a meal. [Let’s assume all tables have four seats and you occupy one seat].

A few minutes later, another person comes in and sits on a seat at another vacant table.

Soon, if all the tables are full [but there are a few vacant seats on some tables], a new patron must negotiate with someone already at a table to be allowed to share the table. [Maybe she may request you to let her occupy the vacant chair at your table, and you may agree].

This process of negotiation is the concept behind a technology called Cognitive Radio, a way to share and optimally utilize unused spectrum. Cognitive Radio is sometimes called Smart Radio because it senses its environment and reacts to it.

The present paucity of radio spectrum is primarily due to the cost and performance limits of legacy hardware established during the past century. Traditionally, radios were hardwired to operate at a particular power and frequency, and once a station was assigned a frequency, no other station could use it. Over the years, as engineers built radios in cheaper and smaller packages, it became possible to build intelligence into them, making the idea of sharing frequencies possible.

Engineers are now working to bring flexible operating intelligence to future radios, cell phones and other wireless communications devices. During the coming decade, cognitive radio technology should enable nearly any wireless system to locate and link to any locally available unused radio spectrum to best serve the consumer. Employing adaptive software, these smart devices could reconfigure their communications functions to meet the demands of the transmission network or the user.

Cognitive Radio will intelligently know, by sensing, adapting and learning, what to do based on prior experiential knowledge, by building an internal database that defines how to best operate in different places and at specific times of day.

As Cognitive Radios send and receive signals, they will nimbly leap and bound in and out of free bands as required, avoiding those that are already in use. This lightning-fast channel jumping will permit cognitive radio systems to transmit voice and data streams at reasonable speeds.

This efficient use of existing Radio Frequency resources will alleviate spectrum-availability traffic jams and wireless communications may become far more dependable, convenient and, perhaps, considerably economical than it is today. Indeed, if Cognitive Radio technology progresses as its developers hope the airwaves will never be the same again.