Introduction
Fiber optic networks refer to the technology that uses glass (or plastic) threads called optical fibers to transmit data. A fiber optic network encodes data into light pulses and sends them through the optical fibers. Optical fibers are capable of transmitting data over long distances with reduced loss compared to electrical cables.
The idea of transmitting light through glass goes back to the 1800s, but practical optical fibers were developed in the 1950s-60s. In 1966, Charles K. Kao and George Hockham proposed using glass fibers for optical communication. The first fiber-optic link was tested in 1970. Through further advancements in the 1970s-80s, optical fibers became a practical way to transmit data over long distances. Today, fiber optics are widely used in telecommunications networks, data centers and more.
Definition of CATS and Catx
CATS and Catx are functions in SAS that are used to concatenate or join together character strings. The key difference between CATS and Catx is how they handle leading and trailing spaces in the strings being concatenated.
CATS stands for “Concatenate and Strip”. When using the CATS function, SAS will remove any leading and trailing spaces from the character variables before concatenating them together (SASCrunch). For example:
data test;
a = “Hello “;
b = “World”;
c = cats(a,b);
run;
In this example, the resulting value of c would be “HelloWorld” with no space between the two words. The leading space after “Hello” and any trailing spaces are stripped out before the concatenation occurs.
In contrast, CATX stands for “Concatenate with Separator”. The CATX function does not strip leading or trailing spaces from the variables. It concatenates the strings as-is, with an optional separator value in between each variable (Statology). For example:
data test;
a = “Hello “;
b = “World”;
c = catx(“-“, a, b);
run;
Here the value of c would be “Hello -World” – the leading space after “Hello” is preserved. So CATX maintains any spacing in the original strings being concatenated.
In summary, CATS strips whitespace and concatenates, while CATX preserves whitespace and adds optional separators between concatenated strings.
Use Cases
Cats and Cats Effect are functional programming libraries for Scala focused on providing abstractions for common programming patterns like handling errors (https://typelevel.org/cats-effect/docs/concepts). They enable pure functional programming in Scala by providing constructs like Monad, Applicative, and Functor from abstract algebra.
On the other hand, CAT5, CAT6, CAT7 etc refer to specifications for twisted pair copper cabling for computer networks. They define requirements for transmission frequencies, cable lengths, resistance, attenuation, crosstalk, and other parameters (https://www.reddit.com/r/scala/comments/7mnhtx/any_good_examples_of_using_cats/).
CAT5 cables are commonly used for networks up to 100 Mbps like Fast Ethernet, while CAT6 cables can support networks up to 10 Gbps like Gigabit Ethernet. CAT7 cables can support even higher frequency networks up to 600 MHz and are sometimes used in data centers.
Differences
The key differences between the CATS and CATX functions in SAS are:
CATS removes leading and trailing blanks and concatenates character variables. CATX inserts delimiters between variables and allows you to specify where to remove blanks.
CATS combines variables end-to-end with no delimiters, while CATX lets you specify a delimiter and insert it between variables. The delimiter can be a space, comma, slash etc.
CATS trims blanks from the start and end of variables before concatenating. CATX allows you to specify where to trim blanks – the start, end or both.
CATS works on character variables only. CATX can work on both numeric and character variables by converting numerics to strings.
In summary, CATX gives you more flexibility and control over concatenation with features like delimiters and specifying where to trim blanks. CATS provides a quicker way to combine variables without these options.
CAT5 Cables
CAT5 cables were widely used for Ethernet networks in the 1990s and early 2000s. CAT5 stands for “Category 5” and refers to the cable standard that provides performance up to 100MHz. CAT5 cables consist of 4 twisted pairs of copper wiring, which helps reduce crosstalk and electromagnetic interference (Wikipedia).
The key specifications of CAT5 cables include:
- Supports speeds up to 100Mbps
- Uses UTP (unshielded twisted pair) copper wiring
- Has 4 pairs of wires
- Max length of 100 meters
While CAT5 was suitable for early Ethernet networks, it has become obsolete in recent years as network speeds have increased beyond 100Mbps. CAT5 has been superseded by standards like CAT5e and CAT6 which enable Gigabit Ethernet connections.
CAT6
The Cat 6 cable specification was finalized in 2002 by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA). Cat 6 cables support bandwidth frequencies of up to 250 MHz and speeds of up to 10 Gbps for distances up to 328 feet (100 meters) (1).
Some key characteristics of Cat 6 cables include (2):
- Made of four twisted copper wire pairs similar to other Cat cables
- Supports Ethernet data rates of up to 10 Gbps
- Uses more stringent standards for system noise and crosstalk
- Requires connectors with better insulation to reduce near-end crosstalk
Overall, Cat 6 provides faster speeds and better noise isolation compared to earlier Cat cable versions, making it well-suited for modern high-bandwidth applications like streaming video and large file transfers within local networks.
CAT7
CAT7 cables are designed to support speeds up to 10Gbps and distances up to 100m (according to stl.tech). They utilize GG45 connectors and are made with shielded twisted pair cabling.
CAT7 has stringent specifications for crosstalk and system noise, allowing it to achieve greater speeds with less signal interference than previous categories (via datapro.net). Shielding in CAT7 protects against electromagnetic interference and alien crosstalk.
Although CAT7 can theoretically support speeds up to 40Gbps in ideal laboratory conditions, it is not commonly used for 40G Ethernet due to the cost and complexity. The Category 7 cable standard was designed primarily to support 10GBASE-T Ethernet.
Cat5e
Cat5e cable is an enhanced version of Cat5 cable that was introduced in 2001. It provides performance of up to 100MHz and can support gigabit Ethernet connections over 100 meter lengths (Ref: Wikipedia).
Some key specifications of Cat5e cable include (Ref: Farnell):
- 4 twisted pairs of copper wire
- 24 AWG wire gauge
- 100 ohm impedance
- Supports speeds up to 1000 Mbps (1 Gbps)
- Frequency tested up to 100 MHz
- Common connector type is RJ45
Cat5e provides better immunity to crosstalk and noise compared to Cat5 cable. It can support many common Ethernet network speeds including 10 Mbps, 100 Mbps, and 1000 Mbps connections. Cat5e is currently the most common type of Ethernet cable used in office and home networks.
Cat6a
Cat6a cables make use of their higher standards by allowing full 10GBASE-T transmission speeds of up to 10 Gbps, at 500MHz of signal bandwidth, over 100 meters (Cat6a cables get this by using thicker twisting techniques).
Being an augmented sixth-generation cable, Cat6a offers super-fast data transfer rates of 10 Gbps up to a length of 100 meters or 328 feet. With 750 MHz bandwidth, Cat6a performs at improved speeds while also reducing crosstalk. It can handle the extremely high bandwidth requirements for applications where there are 40+ Gigabit Ethernet nodes. (Source: https://www.smartechcables.com/blog/cat6a-cable-guide-to-its-types-and-specifications/)
Conclusion
In summary, CATS and CATX are functions in SAS that are used to concatenate or join character variables. The main differences are:
- CATS removes leading and trailing blanks and inserts separators, while CATX only inserts separators.
- CATX allows you to specify where to insert separators, while CATS always inserts them between variables.
- CATX handles both character and numeric variables, but CATS is only for character variables.
- CATS is simpler, but CATX offers more flexibility and control.
For most basic concatenation tasks, CATS is recommended due its simplicity. However, when you need more granular control over separator placement, variable order, data types, etc., then CATX is preferred.
In summary, while their capabilities overlap, think of CATS as quick and straightforward, while CATX has more options and customization. Evaluate your specific needs to determine which one fits best.