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What is the difference between Cellular and PCS? May 17, 2009

Posted by HubTechInsider in Definitions, Fiber Optics, Mobile Software Applications, Telecommunications, Uncategorized, VUI Voice User Interface, Wireless Applications.
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Cellular is dual-classified as being inclusive of both analog and digital networks. Cellular networks began with analog infrastructures, and over time migrated this infrastructure to digital. In a cellular network, depending upon your location throughout the world, the operation frequencies are 800MHz to 900MHz band. Cellular infrastructure is generally based on a macrocell architecture. Macrocells involve a coverage area with a diameter of around 8 miles, and because of this large coverage area, cellular operates at high power levels, in a range of .6 to 3 watts.

PCS is a more recent technology, and has been all digital since inception. As with cellular, depending upon where you are located in the world, the frequency band of operation is in the 1.8GHz to 2GHz band. Instead of cellular macrocells, PCS uses two different infrastructures, both microcell and picocell. As these names imply, the coverage areas of these architectures are smaller than macrocells, around 1 mile in diameter. As a result, PCS uses much lower power levels – 100 milliwatts.

So the key differences between PCS and cellular are the frequencies in which they operate, coverage areas of their different cell architectures, and the power levels each uses to transmit signals. They work essentially the same way, use the same types of network elements, and perform the same functions.

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The SONET and SDH Signal Hierarchy: How many T-1s are in an OC-1, OC-3, OC-12, or OC-48? May 10, 2009

Posted by HubTechInsider in Definitions, Fiber Optics, Telecommunications, Uncategorized.
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I have found that there exists out there in the wide world a touch of confusion when it comes to recognizing the different signal levels and transmission speeds associated with what is referred to in the telecom industry as digital hierarchies, the two most common of which are, in North America, the PDH and SDH, or SONET, hierarchies.

Throughout my work as a telecommunications enthusiast, a pastime of discovery which has kept me occupied ever since my teen years, and on through many of my professional pursuits, I have always served as a point of reference for others in regards to the various telecommunications signal levels as well as the transmission speeds that these levels in the hierarchies represent. The following is my rough attempt to put this information into one place that can serve as a reference for me and others:

SONET was developed to aggregate, or multiplex, circuit switched traffic such as T-1, (E-1 in Europe) T-3, and slower rates of data traffic from multiple sources on fiber-optic networks. SONET transports traffic at high speeds called OC (Optical Carrier). The international version of SONET is called the synchronous digital hierarchy (SDH). SDH carries traffic at synchronous transport mode speeds. Equipment interfaces make SONET and SDH speeds compatible with each other, so the same SONET switching equipment can be used for both OC and SDH speeds.

OC-1 operates at 52 Mbps and is equivalent to 28 DS-1s (same as a T-1) or 1 DS-3 (same as a T-3). OC-1 is generally used as customer access lines. Early-adopter types of customers such as universities, airports, financial institutions, large government agencies, and ISPs – use OC-1.

OC-3 operates at 155 Mbps and is equivalent to 84 DS-1s (same as a T-1) or 3 DS-3s (same as a T-3). OC-3 speeds are required by end users such as companies in the aerospace industry and high-tier ISPs.

OC-12 operates at 622 Mbps and is equivalent to 336 DS-1s (same as T-1) or 12 DS-3s. This is another capacity towards which high-tier ISPs are moving. It was originally deployed for the metropolitan area fiber rings built out across cities worldwide, although those rings are now moving to OC-48.

OC-48 operates at 2,488 Mbps and is equivalent to 1,344 DS-1s (same as a T-1) or 48 DS-3s (same as a T-3). This capacity has been deployed for backbone, or core, networks. Today the metropolitan area rings are moving from OC-48 to OC-192.

OC-192 operates at 9,953 Mbps and is equivalent to 5,376 DS-1s (same as a T-1) or 192 DS-3s (same as a T-3). OC-192 is in use for backbone networks.

OC-768 operates at 39,812 Mbps and is equivalent to 21,504 DS-1s (same as a T-1) or 768 DS-3s (same as a T-3). Use of OC-768 is very rare outside of testing or research networks due to the great expense of this transmission speed level.

At times, you may see OC levels such as OC-1c, OC-3c, OC-12c, etc. This is called concatenation, and it puts streams of data into one fat, or high-bandwidth, contiguous stream. For example, OC-1 speeds of 52 Mbps may be used to carry broadcast video. In this case, OC-1c, or concatenated OC-1, carries OC-1 streams back-to-back. These streams travel contiguously through the network as long as capacity is available. Most applications for concatenation are high-speed data and broadcast-quality video.

As far as the DS, or Digital Signal Levels, of the older PDH, or Plesiochronous Digital Hierarchy (plesiochronous means “minute variations in timing”), they follow what is known as the T-carrier signal levels. Technically, the DS-x and CEPT-x terminology (DS-1, DS-3, CEPT-1, CEPT-3, and so on) indicates a specific signal level (and thus usable bandwidth), as well as the electrical interface specification. T-x and E-x terminology (T-1, T-3, E-1, E-3, and so on) indicates the type of carrier – a specific implementation of a DS-x/CEPT-x. More often than not these days, however, the terms DS-x and T-x are used interchangeably. So some people might use the term DS-1 and T-1 to refer to the same thing – a digital transport that can carry 1.544 Mpbs over a total of 24 voice channels. In Europe, the same is true: E-1 is the same as CEPT-1, and so forth.

A DS-0 (T-0) has a bit rate of 64 Kbps and carries 1 voice-grade channel.

A DS-1 is equivalent to a T-1 and has a bit rate of 1.544 Mpbs and carries 24 voice channels.

A DS-2 has a bit rate of 6.312 Mpbs and carries 96 voice channels, equivalent to 4 T-1s. This is also sometimes referred to as a T-2, or T2.

A DS-3 has a bit rate of 44.736 Mpbs and carries 672 voice channels, equivalent to 28 T-1s. This is also sometimes referred to as a T-3, or T3.

A DS-4 has a bit rate of 274.176 Mpbs and carries 4,032 voice channels, equivalent to 168 T-1s. This is also sometimes referred to as a T-4, or T4.


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About the author.

I’m Paul Seibert, Editor of Boston’s Hub Tech Insider, a Boston focused technology blog. You can connect with me on LinkedIn, follow me on Twitter, even friend me on Facebook if you’re cool. I own and am trying to sell a dual-zoned, residential & commercial Office Building in Natick, MA. I have a background in entrepreneurship, ecommerce, telecommunications and software development, I’m the Senior Technical Project Manager at eSpendWise, I’m a serial entrepreneur and the co-founder of Tshirtnow.net.

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How telephone numbers are assigned May 3, 2009

Posted by HubTechInsider in Definitions, Telecommunications.
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cellphones

The North American Numbering Plan Administration assigns telephone numbers to state-certified wireline carriers in each state. Wireless carriers also receive numbers from the North American Number Plan Administration. However, they don’t need to register on a state-by-state basis because the FCC, not individual states, licenses them to offer service. Carriers such as Vonage, Broadview Networks, and SBC for their IP services are required to obtain telephone numbers from local exchange carriers (LECs) in each state. The LECs can be either the incumbent or a competitor to the incumbent. The reason for this requirement is that VoIP is not defined at this time as a telecommunications service. Thus, VoIP carriers or the department and subsidiaries within carriers that offer VoIP must enter into agreements with a licensed carrier to obtain local telephone numbers in each state in which they wish to offer Voice over IP service. SBC IP has asked the FCC for a waiver of the requirement to obtain numbers from other carriers. In their own territory, they receive num,bers from their parent, SBC. However, when they offer VoIP outside of their home territory, they have to enter agreements with other LECs. Prior to the announced merger with SBC, AT&T objected to SBC IP’s request for a waiver, saying this would be unfair to other VoIP providers.


The North American Numbering Plan Administration assigns numbers in blocks of 1,000. This is called the number pooling system of allotting numbers because pools of 1,000 unused numbers are created. Prior to the year 2000, numbers were assigned to carriers in blocks of 10,000. This resulted in wasted numbers because many smaller carriers who did not use up all of their numbers could not share them with other carriers. To further conserve their numbers, in 2000, the FCC mandated that phone companies must first use up 60% of their assigned phone numbers before being given new ones. As of June 30, 2004, that percentage increased to 75%.

The true meaning of “Getting someone’s Goat” April 30, 2009

Posted by HubTechInsider in Definitions, Uncategorized.
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The expression, “To get someone’s goat”, meaning to anger or irritate, originated in 19th century racing stables in England. High-strung race horses were kept calm by having them share the stables with a goat. Evidently, the company calmed them and allowed them to rest and relax. Unprincipled hooligans would sometimes sneak into the stable at night and remove the goat. The horse got upset, would not have a good rest, and lose the race the next morning.

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An exploration of telecom USOC (pronounced “U-Sock”) codes April 22, 2009

Posted by HubTechInsider in Definitions, Telecommunications, Uncategorized.
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Uniform Service Order Code (pronounced “U-Sock”) is a structured language that allows for the development of software to support service order systems in the telephone industry. The service order process utilizes the USOC, along with Field Identifiers (FIDs), to provision, bill and maintain services and equipment. USOCs can be either three or five alpha/numeric characters. A plus (+) sign indicates a variable suffix position. Suffixes define options of the USOC i.e. color, jurisdiction, speed. To prevent confusion the letter “o” is used and zero is not; the number “1” is used and the letter “I” is not. USOCs are designed for tariffed services, official company services, coin services, equipment, detariffed services, etc. The Bell operating companies in the United States and many independent telephone companies use USOCs to communicate both within their company and between companies. Many new companies in the industry are using the USOC information to interpret incumbent telephone company records when they are supplying new service to a customer. The different companies may have different names for the same services, but the USOC name is generic and therefore becomes a common naming device between companies.





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You’re reading Boston’s Hub Tech Insider, a blog stuffed with years of articles about Boston technology startups and venture capital-backed companies, software development, Agile project management, managing software teams, designing web-based business applications, running successful software development projects, ecommerce and telecommunications.


About the author.

I’m Paul Seibert, Editor of Boston’s Hub Tech Insider, a Boston focused technology blog. You can connect with me on LinkedIn, follow me on Twitter, even friend me on Facebook if you’re cool. I own and am trying to sell a dual-zoned, residential & commercial Office Building in Natick, MA. I have a background in entrepreneurship, ecommerce, telecommunications and software development, I’m the Senior Technical Project Manager at eSpendWise, I’m a serial entrepreneur and the co-founder of Tshirtnow.net.


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The differences between IPT, Internet Telephony, and VoIP April 22, 2009

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People use several IP-realted terms interchangeably. However, according to the International Telecommunications Union (ITU; http://www.itu.int), there are distinctions between the following terms:

* IPT – The transmission of voice, fax, and related services over a packet-switched IP-based network. Internet telephony and VoIP are specific subsets of IPT.

* Internet Telephony – Telephony in which the principal transmission network is the public internet. Internet telephony is commonly referred to as Voice over the Net, Internet phone, and net telephony, with appropriate modifications to refer to fax as well, such as Internet Fax.

* VoIP – IPT in which the principal transmission network or networks are private, managed IP-based networks.





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You’re reading Boston’s Hub Tech Insider, a blog stuffed with years of articles about Boston technology startups and venture capital-backed companies, software development, Agile project management, managing software teams, designing web-based business applications, running successful software development projects, ecommerce and telecommunications.


About the author.

I’m Paul Seibert, Editor of Boston’s Hub Tech Insider, a Boston focused technology blog. You can connect with me on LinkedIn, follow me on Twitter, even friend me on Facebook if you’re cool. I own and am trying to sell a dual-zoned, residential & commercial Office Building in Natick, MA. I have a background in entrepreneurship, ecommerce, telecommunications and software development, I’m the Senior Technical Project Manager at eSpendWise, I’m a serial entrepreneur and the co-founder of Tshirtnow.net.

A brief history of the Aspect Ratio April 21, 2009

Posted by HubTechInsider in Definitions, Technology, Video Gaming Video Games.
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common (image) aspect ratio found in video.

Image via Wikipedia

The 4:3 aspect ratio was originally developed by W.K.L.Dickson in 1889 while he was working at Thomas Edison’s laboratories. Dickson was experimenting with a motion-picture camera called a Kinescope, and he made his film 1 inch wide with frames 0.75 inches high. This film size, and its aspect ratio, became the standard for the film and motion-picture industry because there was no apparent reason to change it. In 1941, when the NTSC proposed standards for television broadcasting, they adopted the same ratio as the film industry.

In the 1950’s, Hollywood wanted to give the public a reason to buy a ticket to attend the theatre rather than sit at home watching the TV. Because our two eyes give us a wider view, a wider movie makes more sense. Widescreen formats are formatted much closer to the way we see. Our field of vision is more rectangular than square. When we view movies in widescreen format, the image fills more of our field of vision and has a stronger visual impact. Wider screens gave the theatre audience a more visually engulfing experience. The 16:9 aspect ratio allows TV to move closer to the movie experience.

Want to know more?

You’re reading Boston’s Hub Tech Insider, a blog stuffed with years of articles about Boston technology startups and venture capital-backed companies,software development, Agile project management, managing software teams, designing web-based business applications, running successful software development projects, ecommerce and telecommunications.

About the author.

I’m Paul Seibert, Editor of Boston’s Hub Tech Insider, a Boston focused technology blog. I have been working in the software engineering and ecommerce industries for over fifteen years (I got started with computers really early). My interests include electronics, robotics and programmable microcontrollers, and I am an avid outdoorsman and guitar player. You can connect with me on LinkedIn, follow me on Twitter, even friend me on Facebook if you’re cool. I own and am trying to sell a dual-zoned, residential & commercial Office Building in Natick, MA. I have a background in entrepreneurship, ecommerce, telecommunications andsoftware development, I’m the Director, Technical Projects at eSpendWise, I’m a serial entrepreneur and the co-founder of Tshirtnow.net.

An explanantion of telecommunications industry CLLI “Silly” Codes April 20, 2009

Posted by HubTechInsider in Definitions, Fiber Optics, Telecommunications, Uncategorized, Wireless Applications.
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What the heck is a “Silly” Code? Allow me to explain…

A CLLI, (pronounced “Silly”) code is a telecommunications industry-standard and is an alphanumeric code of 11 characters, CLLI was developed by Bellcore (now telecordia Technologies) as a method of identifying physical locations and equipment such as buildings, central offices, poles, and antennas. Each CLLI code conforms to one of three basic formats (Network Entity, Network Support Site and Customer Site). Each format, in turn, determines how these six coding elements are used:

Geographical Codes (Example: DNVR = Denver) Typically assigned to cities, towns, suburbs, villages, hamlets, military installations and international airports, geographical codes can also be mapped to mountains, bodies of water and satellities in fixed-earth orbit.

Geopolitical Codes (Example: CO = Colorado) Typically assigned to countries, states and provinces, geopolitical and geographical codes can be combined to form a location identifyer that is unique worldwide.

Network Site Codes (Example: 56 = A Central Office on Main Street) This element is used with geographical and geopolitcal codes to represent buildings, structures, enclosures or other locations at which there is a need to identify and describe one or more functional entities. This category includes central office buildings, business and commercial offices, certain microwave-radio relay buildings and earth stations, universities, hospitals, military bases and other government complexes, garages, sheds and small buildings, phone centers and controlled environmental vaults.

Network Entity Codes (Example: DS0 = A digital switch) This element can be used with geographical, geopolitical and network-site codes to identify and describe functional categories of equipment, administrative groups or maintenance centers involved in the operations taking place at a given location.

Network Support Site Codes (Example: P1234 = A telephone pole) This element can be used with geographical and geopolitical codes to identify and describe the location of international boundaries or crossing points, end points, fiber nodes, cable and facility junctions, manholes, poles, radio-equipment sites, repeaters and tall stations.

Customer Site Codes (Example: 1A101 = A Customer) This element can be used with geographical and geopolitical codes to identify and describe customer locations associated with switched-service networks, centrex installations; Trunk forecasting, cable, carrier or fiber terminations, NCTE, CPE and PBX equipment, military installations, shopping malls, universities and hospitals.

Consider the real-life example of NYCMNY18DS0. The first four characters identify the place name (NYCM is New York City Manhattan). The following two characters identify the state, region, or territory (NY is New York). The remaining five chracters identify the specific item at that place (18DS0 is the AT&T 5E Digital Serving Office on West 18th Street, between Seventh and Eighth Avenues). Phone companies use CLLI Codes for a variety of purposes, including identifying and ordering private lines and trapping and tracing of annoying or threatening calls.

CLLI Code – Facility Identification codes provide unique identification of facilities (cable and carrier systems) between any two interconnected CLLI coded locations. The CLFI code is a variable length, mnemonic code with a maximum of 38 characters. Example: 101T1LSANCA03NWRKNJAA. This example says that there is a T-1 carrier connected between the Los Angeles, California Central Office to the Newark, New Jersey Central Office.





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You’re reading Boston’s Hub Tech Insider, a blog stuffed with years of articles about Boston technology startups and venture capital-backed companies, software development, Agile project management, managing software teams, designing web-based business applications, running successful software development projects, ecommerce and telecommunications.


About the author.

I’m Paul Seibert, Editor of Boston’s Hub Tech Insider, a Boston focused technology blog. You can connect with me on LinkedIn, follow me on Twitter, even friend me on Facebook if you’re cool. I own and am trying to sell a dual-zoned, residential & commercial Office Building in Natick, MA. I have a background in entrepreneurship, ecommerce, telecommunications and software development, I’m the Senior Technical Project Manager at eSpendWise, I’m a serial entrepreneur and the co-founder of Tshirtnow.net.

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