T-Mobile US, Inc.  is an American wireless network operator headquartered in Overland Park, Kansas, and Bellevue, Washington, U.S. Its largest shareholder is multinational telecommunications company Deutsche Telekom AG, which , holds a 51.4% majority stake in the company. T-Mobile US is the third-largest wireless carrier in the United States, with 116.7 million subscribers at the end of Q2 2023.

The company was founded in 1994 by John W. Stanton of the Western Wireless Corporation as VoiceStream Wireless. Deutsche Telekom then gained plurality ownership in 2001 and renamed it after its T-Mobile brand. T-Mobile US provides wireless voice and data services in the United States under the T-Mobile and Metro by T-Mobile brands (the latter was acquired via the purchase of MetroPCS in a reverse takeover in 2013, resulting in T-Mobile going public on the NASDAQ stock exchange), and also serves as the host network for many mobile virtual network operators. The company has annual revenues of around $80 billion. In 2015, Consumer Reports named T-Mobile the number one American wireless carrier.

On April 1, 2020, T-Mobile and Sprint Corporation completed their merger, with T-Mobile now being the sole owner of Sprint, making Sprint an effective subsidiary of T-Mobile until the Sprint brand was officially discontinued on August 2, 2020, with the headquarters becoming T-Mobile offices. As part of the merger, T-Mobile US acquired Assurance Wireless, the service subsidized by the Lifeline Assistance program of the federal Universal Service Fund.

History
T-Mobile U.S. traces its roots to the 1994 establishment of VoiceStream Wireless PCS as a subsidiary of Western Wireless Corporation. After its spin off from parent Western Wireless on May 3, 1999, VoiceStream Wireless was purchased by Deutsche Telekom AG in 2001 for $35 billion and renamed T-Mobile USA, Inc., in July 2002. In 2013, T-Mobile and MetroPCS finalised a merger of the two companies which started trading as T-Mobile U.S.

VoiceStream Wireless

VoiceStream Wireless PCS was established in 1994 as a subsidiary of Western Wireless Corporation to provide wireless personal communications services (PCS) in 19 FCC-defined metropolitan service areas in several western and southwestern states using the GSM digital wireless standard. VoiceStream Wireless' digital, urban service areas complemented the analog, rural service areas marketed by Western Wireless under the Cellular One brand.

Western Wireless spun off its VoiceStream Wireless division into a new company called VoiceStream Wireless Corporation in May 1999.

Omnipoint and Aerial acquisitions
In 2000, VoiceStream Wireless acquired two regional GSM carriers. Omnipoint Corporation, a regional network operator in the Northeastern U.S., was acquired on February 25, 2000. Aerial Communications Inc.; a regional network operator in the Columbus, Houston, Kansas City, Minneapolis-St. Paul, Pittsburgh, and Tampa-St. Petersburg-Orlando markets; was acquired on May 4, 2000. The combined company retired the Omnipoint and Aerial brands and completed integrating the three companies by converting to a single customer billing platform, implementing standard business practices and launching the VoiceStream brand and "GET MORE" marketing strategy in all markets.

Deutsche Telekom acquires VoiceStream and Powertel

On June 1, 2001, Deutsche Telekom (DT) completed its acquisition of VoiceStream Wireless, Inc., for $35 billion and Southern U.S. regional GSM network operator Powertel, Inc., for $24 billion. By the end of 2001, VoiceStream Wireless had 19,000 employees serving 7 million subscribers.

On September 2, 2001, VoiceStream Wireless Inc. adopted the name, T-Mobile USA, Inc. and began rolling out the T-Mobile brand, starting with locations in California and Nevada. T-Mobile USA, Inc. was an operating entity of T-Mobile International AG, before becoming a direct subsidiary of Deutsche Telekom AG. The merger became official in July 2002.

SunCom acquisition
On September 17, 2007, the company announced the acquisition of regional GSM carrier SunCom Wireless Holdings, Inc. for $2.4 billion; the acquisition closed on February 22, 2008. By September 8, 2008, SunCom's operations were integrated with those of the company. The acquisition added SunCom's 1.1 million customers to the company's customer base and expanded the company's network coverage to include southern Virginia, North Carolina, South Carolina, eastern Tennessee, northeastern Georgia, Puerto Rico and the U.S. Virgin Islands. Following the Suncom acquisition, T-Mobile possessed native network presence in all the major metro areas in the United States.

Aborted acquisition by AT&T

On March 20, 2011, AT&T announced its intention to purchase T-Mobile US from Deutsche Telekom. The Antitrust Division of the United States Department of Justice responded by filing a federal lawsuit on August 31, 2011, to block the merger. AT&T then decided to formally abandon the merger bid on December 19, 2011.

Merger with MetroPCS Communications
On October 3, 2012, MetroPCS Communications reached an agreement to merge with T-Mobile USA. MetroPCS shareholders would hold a 26% stake in the company formed after the merger, which retained the T-Mobile brand. While the new company was still the fourth-largest carrier in the United States (at the time), the acquisition gave T-Mobile access to more spectrum and financial resources to maintain competitiveness and expand its LTE network. The merger between T-Mobile USA Inc. and MetroPCS was officially approved by MetroPCS shareholders on April 24, 2013. The deal was structured as a reverse takeover; the combined company went public on the New York Stock Exchange as TMUS and became T-Mobile U.S. Inc. on May 1, 2013. The merger agreement gave Deutsche Telekom the option to sell its 72% stake in the company formed by the merger and valued at around $14.2 billion to a third party before the end of the 18-month lock-up period.

The "Un-carrier", additional wireless spectrum acquisition
In March 2013, T-Mobile introduced a major overhaul of its plan structure, marketed by branding themselves as being "the Un-carrier". A new contract-free pricing structure with simpler plans was introduced in which a phone's cost is paid over a two-year financing plan. The "Un-carrier" strategy has since been expanded to encompass other value-added services, such as a plan add-on allowing phone trade-ins for early upgrades twice per year, carrying over unused data allotments for up to a year, and zero-rating of selected music and video services (the latter locked to "DVD quality") over the mobile network, These moves came as part of an effort under new CEO John Legere to help revitalize the business as it improves its network quality.

Though this system is said to improve network quality, issues surrounding net neutrality infringement have also come to light. The type of zero-rating that is offered by T-Mobile allows it to charge higher rates to third-parties, meaning that ISP can prioritize the company that pays a higher premium. This makes it more difficult for smaller third-parties who are unable to pay the high premium charged by the ISP.

On June 28, 2013, T-Mobile agreed to buy wireless spectrum for the Mississippi Valley region from its competitor U.S. Cellular for around $308 million, allowing it to expand its 4G network across 29 more markets.

On January 6, 2014, T-Mobile signed agreements with Verizon Wireless to purchase some 700 MHz A-Block spectrum licenses for $2.365 billion. Moreover, a transfer of some AWS and PCS spectrum licenses with a value of $950 million has been agreed upon by T-Mobile and Verizon. The acquisition reportedly gave T-Mobile additional coverage for approximately 158 million people in 9 of the top 10 and 21 of the top 30 U.S. markets.

Merger with Sprint Corporation

On April 29, 2018, T-Mobile US and Sprint Corporation announced their intention to merge. Although the U.S. Justice Department initially approved the merger on July 26, 2019, the attorneys generals from several states filed a lawsuit in the U.S. District Court for the Southern District of New York to block it, alleging that the merger would result in higher prices for consumers in the range of $4.5 billion annually. District Judge Victor Marrero then announced his decision in favor of the merger on February 11, 2020, stating that it "is not likely to substantially lessen competition like the suing [states] had claimed it would" and that Sprint "does not have a sustainable long-term competitive strategy" to remain a viable competitor.

The merger finally closed on April 1, 2020, and then the Sprint brand was officially discontinued on August 2, 2020. Leadership, background and stock changes happened immediately, with customer-side changes happening over time. Billing was already showing the T-Mobile brand, and all retail, customer service, and all other company branding switched to the T-Mobile brand. T-Mobile and Sprint accounts were still managed by employees in separate systems and the company still offered Sprint branded SIM cards. New rate plans were also introduced as well for all new and existing customers from both companies, though all were grandfathered into their current plan should they choose not to switch to a new T-Mobile plan for at least three years.

As part of the Sprint merger, T-Mobile US acquired Assurance Wireless, the service subsidized by the Lifeline Assistance program of the federal Universal Service Fund.

Acquisition of Mint Mobile and Ultra Mobile
In March 2023, T-Mobile US agreed to acquire Ka'ena Corporation as well as subsidiaries and brands: Mint Mobile, a successful budget direct-to-consumer prepaid wireless brand in the US, and Ultra Mobile, a wireless service that offers offering international calling options to communities across the country, for up to $1.35 billion. It was noted that Ryan Reynolds who owns a majority stake in Mint Mobile will stay on as Mint's official spokesman. The deal is expected to close later this year, and the final price will be based on Ka'ena's performance.

Wireless networks
The company owns licenses to operate a cellular communications network in the 1900 MHz (PCS) and 1700 MHz (AWS) bands with coverage in many parts of the continental U.S., Hawaii, Puerto Rico, and the U.S. Virgin Islands, as well as licenses in the 700 MHz band (block A mostly) available in certain parts of the country. In 2017 T-Mobile also acquired a nationwide 600 MHz license. It deployed this spectrum over the following few years as it was vacated by television stations across the country in stages. With respect to technology, depending on the location, in the 1900 MHz band it deploys GSM and/or LTE (Band 2 and 25); in the 1700 MHz band it deploys LTE (B4 and B66); LTE in the 700 MHz (B12) and 850 MHz (B5) bands; LTE and 5G NR on 600 MHz (B71) and 2500 MHz (B41) bands; and 5G NR only on 24 GHz (n258), 28 GHz (n261) and 39 GHz (n260) bands. Its LTE network also supports VoLTE. It provides coverage in areas where it does not own radio frequency spectrum licenses via roaming agreements with other operators of compatible networks. T-Mobile began its VoNR rollout in June 2022.

Cellular network

2G GSM

The company's predecessor, VoiceStream Wireless, began building a regional, 2G, 1900 MHz GSM, circuit-switched, digital cellular network in 1994 and first offered service in 1996 in Honolulu and Salt Lake City. From that starting point, the network has expanded in size through acquisitions of other cellular-network operators and additional spectrum purchases. The network has also expanded in capabilities through the introduction of new technologies. VoiceStream upgraded the 1900 MHz network to include packet switching via General Packet Radio Service (GPRS), then increased packet-switched data transmission speeds via Enhanced Data Rates for GSM Evolution. In 2006, the company spent $4.2 billion to purchase 120 D, E or F block 1700 MHz AWS licenses and began rolling out 3G UMTS services in those frequency bands. The company upgraded network equipment and back-haul capabilities to enable HSPA (High Speed Packet Access), and later HSPA+ and LTE services.

Packet-switched data service first became available to users in the form of General Packet Radio Service (GPRS). Packet-switched data speeds increased when Enhanced Data Rates for GSM Evolution (EDGE) was incorporated into the network. EDGE coverage was available within at least forty percent of the GSM footprint.

Both voice capacity and packet-switched data speed improved when 3G Universal Mobile Telecommunications System (UMTS) equipment was installed in the network. On January 5, 2010, the company announced that it had upgraded its entire 3G network to HSPA 7.2 Mbit/s, an improvement from its previous peak of 3.6 Mbit/s. It also said that it planned to be the first U.S. carrier to deploy HSPA+ across its network by mid-2010. The company had finished HSPA+ trials in Philadelphia, Pennsylvania, and had begun deploying HSPA+ across its network. T-Mobile plans to shut down its GSM network on April 2, 2024.

3G UMTS
In September 2006, the Federal Communications Commission (FCC) auctioned licenses in the first Advanced Wireless Services band. This band was an area of wireless spectrum, half in the 1700 MHz and half in the 2100 MHz frequencies, that was already in use by government services. The spectrum was planned to become available after the government users migrated to different frequencies.

The auction made numerous licenses available in overlapping market-areas, economic-areas, and regional levels. Each license was individually bid upon, and T-Mobile USA was the winner in 120 license auctions, at an aggregate price of $4.18 billion. As part of its winnings, T-Mobile USA gained nationwide coverage of 1.7 GHz and 2.1 GHz, with numerous areas being supplemented with additional licenses. Examples include New York City, Chicago, and Boston where T-Mobile USA acquired one-third (33 percent) of the available spectrum, or San Francisco, Houston, and Miami where they acquired 45 percent of the available spectrum.

On October 6, 2006, two weeks after confirming its winning bids, the company announced its intentions to create a UMTS third-generation, or 3G, cellular network with the spectrum it had won. It said it would utilize and build on the experience of T-Mobile International's European subsidiaries, which already implemented 3G networks. At the time of initial roll-out, the company intended to offer 7.2 Mbit/s service, making the company's 3G network the fastest in the U.S. The upgrade was forecast to cost $2.6 billion, in addition to the $4.12 billion spent to acquire the spectrum licenses.

In the same announcement, the company indicated it had already begun to deploy about half of the upgraded equipment, beginning in major markets such as New York City. With the equipment in place, it would be able to activate its network as soon as the government agencies vacated the spectrum. The company had hoped to have its network activated by mid-2007, but as of September 2007, the government users had not vacated the AWS band.

The company began selling its first 3G-capable phone, the Nokia 6263, in November 2007 and announced in February 2008 that its 3G network would finally be activated "within the next few months". and released in the New York City market on May 1, 2008.

By 2009, the company had launched its 3G network in more than 200 markets, covering some 208 million points of presence (POPS). On June 28, 2010, the company announced that it would begin to upgrade its network from HSPA+ 21 to HSPA+ 42 beginning sometime in 2011. T-Mobile also markets HSPA and HSPA+ services as 4G. Throughout 2015, T-Mobile began refarming UMTS/HSPA services from the original AWS band to their PCS band to expand bandwidth available for LTE. This rendered a select number of T-Mobile 3G devices inoperable on the 3G network. T-Mobile shut down its UMTS network on July 1, 2022.

4G LTE
On February 23, 2012, during the Q4 Earnings Call, T-Mobile laid out the future of their 4G upgrade path. They would roll out the LTE network on the AWS spectrum, and transition their HSPA+ network to the PCS band. To achieve compatibility with other networks and phones in the US, T-Mobile began this transition in March 2013, and the rollout of LTE is currently underway as T-Mobile expands to more markets. Due to the failed acquisition of T-Mobile USA by AT&T, T-Mobile USA received additional UMTS frequency band 4 (AWS) spectrum. On March 26, 2013, T-Mobile began rolling out LTE in 7 markets: Baltimore, San Jose, Washington, D.C., Phoenix, Las Vegas, Kansas City, and Houston.

On August 21, 2012, the FCC approved a deal between T-Mobile and Verizon in which T-Mobile gained additional AWS spectrum licenses in 125 Cellular Market Areas.

On February 25, 2014, T-Mobile announced in its Q4 2013 earnings call that its 4G LTE network covered 209 million people in 273 metro areas. They also planned to start rolling out their 700 MHz A-Block spectrum by the end of 2014, which by the end of the rollout would cover 158 million people. This spectrum led to improved LTE coverage overall in these areas, particularly indoors.

On March 13, 2014, T-Mobile announced a new plan to upgrade its entire 2G/EDGE network to 4G LTE. They expected 50% to be done by the end of 2014, and it to be "substantially complete" by the middle of 2015.

On December 16, 2014, T-Mobile announced during CEO John Legere's Un-carrier 8.0 interview that their 4G LTE network covered 260 million people and their 700 MHz Band 12 LTE had been rolled out in Cleveland, Colorado Springs, Minneapolis, and Washington, D.C. They expected to cover 280 million with LTE by mid-2015 and 300 million by the end of 2015. They also stated that they covered 121 metro areas with their Wideband LTE.

On October 27, 2015, T-Mobile announced in its Q3 2015 earnings call that they covered over 300 million people with LTE, reaching their 2015 end of year goal months ahead of schedule.  They had 245 markets with Wideband (at least 15+15 MHz) LTE.  They also had 204 markets with Extended Range 700 MHz Band 12 LTE covering around 175 million people.  Their coverage map revealed that they now had new native LTE coverage in Montana, the Dakotas, Eastern West Virginia, and Northern Michigan.

On May 25, 2016, T-Mobile announced that it will be purchasing the 700Mhz A-block license (LTE band 12) for the Chicago metro area. When this transaction closes, together with several other pending 700Mhz license acquisitions, T-Mobile expects to possess 700Mhz licenses covering a total of 272 million people, or 84% of the US population – including 10 of the top 10 largest US metro areas. T-Mobile refers to its 700Mhz low-band network as 'Extended-range LTE' and claims it penetrates buildings and reaches out farther than its PCS and AWS only network. In September 2016, T-Mobile launched 4x4 MIMO and 3 channel carrier aggregation allowing theoretical speeds of 400 Mbit/s, and also announced that the company's LTE network reaches over 312 million potential subscribers.

In early 2017, T-Mobile purchased 45% of available 600 MHz spectrum in the US, covering 100% geographically of the US. They started the rollout of LTE on this band on August 15, 2017.

In 2018 T-Mobile has stated they will not discontinue rollout and upgrades of LTE in favor of 5G. Instead, they will continue to grow and support their LTE network to work simultaneously with 5G.

As of January 22, 2019, the LTE-Advanced upgrade has been deployed in 6,000 cities and towns.

As of October 28, 2019, LTE now covers 326 million people.

As of February 6, 2020, the 600 MHz network reaches 8,900 cities and towns, covering 248 million people.

5G NR

Preparations
On June 25, 2018, T-Mobile and Nokia completed their first bi-directional 5G NR transmission in the 28 GHz frequency compliant with 3GPP 5G standards, showing a big step forward to building a nationwide 5G Network.

On November 20, 2018, T-Mobile and Nokia completed their first downlink 5G NR transmission in the 600 MHz frequency compliant with 3GPP 5G standards in Spokane, Washington. 28 GHz only reaches roughly , whereas 600 MHz can reach hundreds of square miles. This marks one step closer to a rural 5G network, one highly sought improvement with 5G technology (high-speed data in rural areas).

On January 7, 2019, T-Mobile and Ericsson completed the first audio and video call using a live 5G NR network using 3 separate frequency bands; 600 MHz, 28 GHz, and 39 GHz. This was also the first live network test with successful uplink and downlink.

On July 11, 2019, T-Mobile and Ericsson completed their first n71 (600 MHz) data session in their lab in Bellevue, Washington on a commercial 5G modem, the Snapdragon X55, which is the first commercial 5G modem to feature the n71 band. However, the modem was pre-market and not in any commercially available device.

Vendors
On July 30, 2018, T-Mobile and Nokia announced a $3.5 billion contract for equipment and software to build out a nationwide 5G network that will be compliant with 3GPP 5G standards. The network will use the 600 MHz and 28 GHz frequency bands.

On September 11, 2018, T-Mobile and Ericsson announced a $3.5 Billion contract for equipment to build out a nationwide 5G network that will be compliant with 3GPP 5G standards. The network will use the 600 MHz and 28 GHz frequency bands. This marked $7 billion invested in T-Mobile's 5G network, which will use both companies equipment.

Launches
On February 26, 2018, T-Mobile announced it would roll out 5G to 30 cities by the end of 2018, with compatible handsets delivering early 2019. They also stated their 5G network will be able to work simultaneously with their 4G LTE network, delivering faster speeds and broader range.

On June 28, 2019, T-Mobile officially launched their 5G mmWave network with the launch of their first commercially available 5G NR device, the Galaxy S10 5G. The network has launched in 6 cities; Los Angeles, NYC, Atlanta, Dallas, Las Vegas, and Cleveland.

On August 4, 2020, T-Mobile launched standalone (SA) mode across their national 5G network, becoming the first operator in the world to do so. They also stated SA mode improved 5G coverage because a connection to a mid-band LTE cell was no longer required as it was in non-standalone mode (NSA).

Extended-Range 5G
On November 7, 2019, T-Mobile announced that its 600 MHz 5G network will launch on December 6, 2019. The network will launch alongside the first two 600 MHz 5G-capable devices, the Samsung Galaxy Note 10+ 5G and the OnePlus 7T Pro 5G McLaren Edition.

On December 2, 2019, T-Mobile officially launched its 600 MHz 5G network. It launched with an initial coverage of 200 million people and over 5,000 cities or towns.

As of February 15, 2023, T-Mobile's 600 MHz network covers an estimated 323 million pops.

Ultra Capacity 5G
On April 21, 2020, T-Mobile launched the T-Mobile branded 2.5 GHz as Ultra-Capacity 5G with the spectrum it acquired in the Sprint merger in Philadelphia. On October 2023, the company announced that their Ultra-Capacity 5G (including PCS, 2.5 GHz and 24/28/39 GHz) currently covers over 300 million pops, by providing an average speed of 400 MB/s, two months ahead of schedule by the year-end.

T-Mobile also stated that the same network will go live in New York, NY, the first city with all 3 parts of T-Mobile's "layer cake" strategy to 5G NR of having 3 separate bands on low, mid and high band frequencies.

T-Mobile has also acquired C-Band 3.7 GHz licenses in early 2021 for an average of 40 MHz of spectrum covering 225 million people nationwide, bidding over $9.3 billion in licenses. This spectrum is currently pending and is going be in use by the end of 2023, adding an additional layer of "Ultra-Capacity 5G" with deployment starting in early 2023.

On January 31, 2022, T-Mobile announced that they have bid on C-Band 3.45 GHz licenses for approximately $3 billion from Auction 110 auctioned off by Federal Communications Commission for an average of 21 MHz of spectrum to bring up to 184 million people covered across the United States, placing second behind AT&T. T-Mobile intends to deploy this spectrum alongside its C-Band holdings in 2023.

Roaming
T-Mobile has roaming arrangements with a number of national and regional mobile network operators, including AT&T Mobility.

As of 2008, prepaid customers have almost all of the postpaid domestic roaming privileges and restricted international roaming to Canada and Mexico.

In 2009, T-Mobile USA began removing AT&T Mobility roaming coverage in many locations across the country, and updated its on-line coverage maps to reflect the smaller coverage area. AT&T Mobility roaming remains available in select locations, primarily on smaller carriers that were acquired by AT&T Mobility after long-term roaming contracts were in place between T-Mobile and the smaller carriers, including Centennial Wireless and Edge Wireless.

On June 29, 2010, the company launched voice service in the Gulf of Mexico on GSM via roaming agreement through Broadpoint. T-Mobile USA was scheduled to launch data service in Fall 2010. Also in 2010, T-Mobile US became a member of the FreeMove alliance.

On October 9, 2013, T-Mobile announced Simple Global, a service included with eligible Simple Choice plans. This service allows one to roam in over 100 countries with unlimited text and speed-limited data, and make calls at $0.20/minute. High-speed data passes will be available for purchase. On March 7, 2014, T-Mobile announced this number will be increasing to 122 countries. If one is connected to WiFi in one of these countries, and their phone supports WiFi calling, all calls and texts to and from the US are free, and work the same as if they were on the cellular network.

On July 15, 2015, T-Mobile launched Mobile Without Borders, a service included with all new T-Mobile plans and available as an add-on to grandfathered or promotional plans for $10. This service allows the user to use their normal voice, text message, and data allotments while roaming in Mexico and Canada. Most T-Mobile services are available while roaming, with the notable exception of using the data in one's Data Stash.

In August 2015, T-Mobile joined the Competitive Carriers Association's Data Services Hub, enabling the company to expand roaming partnerships with over a dozen rural and regional carriers. Smaller carriers will now be able to access T-Mobile's LTE network for roaming and T-Mobile will be able to expand roaming partnerships and extend its footprint with members whose network technologies had previously been incompatible.

In October 2017, T-Mobile announced that starting November 12, 2017, LTE-speeds will be limited at 5 GB (with speeds going at speeds at 128 kbit/s or 256 kbit/s on some plans) while data roaming in Canada and Mexico still remains unlimited. However, calling and texting in these countries still remain free from roaming charges. T-Mobile also announced a partnership with US Cellular in California, Iowa, Washington, and Wisconsin to expand 4G LTE coverage. Compatible device required.

In August 2022, T-Mobile and SpaceX announced a partnership called Coverage Above and Beyond where the latter's satellites would provide connections for cellphones throughout the US, even in remote areas with no existing service. The goal was to allow customers to have service everywhere, with no dead zones. Starlink satellites would function like cell towers. At the time of announcement, the plan was to start with text messages and messaging apps and using existing hardware as opposed to new phones.

Radio frequency spectrum chart

T-Mobile network
The following chart describes radio frequency spectrum bands accessible by the company's customers.

Past networks

The following chart lists the networks that T-Mobile previously operated.

Sprint network

Sprint's network was decommissioned and integrated into T-Mobile's network. The CDMA network was completely shut down on May 31, 2022 and the LTE network was discontinued on June 30, 2022. Sprint used bands 25, 26 and 41 to provide LTE coverage and used band n41 for NR coverage.

T-Mobile HotSpots
T-Mobile has used the term "Hotspot" to represent various products and technologies.

Wi-Fi network (public)

The company operates a nationwide Wi-Fi Internet access network under the T-Mobile HotSpots brand. The T-Mobile HotSpots network consists of thousands of Wi-Fi access points installed in businesses, hotels, and airports throughout the U.S.

The T-Mobile HotSpot service offers access to a nationwide network of approximately 8,350 access points, installed in venues such as Starbucks coffeehouses, FedEx Office Office and Print Centers, Hyatt hotels and resorts, Red Roof Inns, Sofitel hotels, Novotel hotels, the airline clubs of American Airlines, Delta Air Lines and United Airlines, as well as airports.

The T-Mobile HotSpots network can be traced to the company's 2002 purchase of bankrupt wireless ISP MobileStar, which began building its network in 1998. After completing the purchase, the company expanded the network into 400 Borders bookstores, as well as 100 of the most-frequented airport clubs and lounges operated by American Airlines, Delta Air Lines, and United Airlines.

On September 14, 2014, T-Mobile partnered up with GoGo to provide free texting on airplanes for its customers. GoGo services are provided on Delta Air Lines, American Airlines, United Airlines and Alaska Airlines.

On June 6, 2016, T-Mobile expanded its partnership with GoGo to offer T-Mobile users one hour of free WiFi on customers phones while T-Mobile One Plus and One Plus International users also get free WiFi throughout the entire flight. T-Mobile also included other messaging apps (iMessage, Google Hangouts, WhatsApp and Viber) in addition to SMS texting being provided since September 2014.

Wi-Fi network (private)
T-Mobile has also used the term to describe Wi-Fi Access Points that it sold to end users to expand their cell phone network to phones equipped to also receive Wi-Fi using a VOIP-like technology.  (The models included at least two by Linksys: the WRTU54G-TM and the WRT54G-TM and one by D-Link: the TM-G5240.)

Finances
For the fiscal year 2017, T-Mobile US reported earnings of US$4.481 billion, with an annual revenue of US$40.604 billion, an increase of 8.3% over the previous fiscal cycle. T-Mobile's shares traded at over $62 per share and its market capitalization was valued at over US$58.1 billion in November 2018.

Products and services

Mobile phone & data

Go5G and Go5GPlus, plus Essentials
In April 2023, the company announced its new Go5GPlus and Go5G plans.

The Go5GPlus plan offering represented a bigger change. It guaranteed a two-year device payment plan for both new and existing customers and took the place of the Magenta Max as the most expensive plan. The cost was $90 per month and included everything Magenta Max offered, like Netflix and AppleTV+, as well as an extra 10GB of premium mobile hotspot data for a total of 50GB per month and 15GB of high-speed data in Canada and Mexico.

The Go5G plan offered a greater amount of data.

There were also version of these plans for small businesses, customers 55-years-old and up, and military families.

Additionally, the company unveiled a "limited time" plan called "Essential Savings" that lowered the price to $50 from $60.

These plans were announced on April 20, or 4/20, a reference to pot consumption. The Verge noted T-Mobile's aim to "smoke the competition" had "some real 'How do you do, fellow kids?' energy," in reference to actor Steve Buschemi appearing out of touch on sitcom "30 Rock."

Magenta MAX
On January 22, 2021, it was announced that T-Mobile unveiled its newest 5G smartphone plan that offers no throttling called T-Mobile Magenta MAX, the first U.S. wireless carrier to do so. Customers get unlimited Premium Data (4G and 5G), unlimited 4K UHD video streaming, Netflix on Us for single line plans, mobile high-speed hotspot data at 40GB,  Unlimited talk, text, and data in Mexico and Canada with up to 5GB of high-speed data, T-Mobile Tuesdays free thank you gifts and discounts, unlimited Gogo in-flight texting and Wi-Fi all flight long, free texting and data in 210 countries and destinations, and free Scam Shield Premium protection, including free Scam Block and Caller ID. Magenta MAX cost the same as the Magenta Plus plan at $57 per line per month for three lines with autopay with taxes and fees included.

Magenta & Magenta Plus
On June 2, 2019, T-Mobile announced the launch of Magenta and Magenta Plus plans to phase out and replace the T-Mobile ONE family of plans. The Magenta family of plans build on the existing features of the T-Mobile ONE and ONE Plus plans, but now include additional features like 3GB of Mobile HotSpot Data for standard Magenta plans, and retaining the same enhanced HD Streaming, 20GB of Mobile HotSpot Data, and other features of the T-Mobile ONE Plus plans.

T-Mobile has discontinued the Magenta Plus plan but upgrades their Magenta plan by providing 100 GB of premium data and bumping the high-speed hotspot data to 5 GB without overall price change.

Military, First Responder, and Unlimited 55+
Alongside the T-Mobile Magenta family of plans are the specialized plans offered to Military personnel, First Responders, and seniors age 55 and up.

Military and First Responder plans allow for qualified service members to receive 50% off of standard pricing Magenta and Magenta Plus plans. Customers must verify their affiliation within 45 days of activation or switching to the plan in order to retain the discounted offer.

The Unlimited 55+ allows customers at or over the age of 55 to receive a set discounted price on standard rate plans, however these accounts are limited to only 2 lines per account. Certain customers were permitted to add a third line to their account during a specific promotional period.

T-Mobile ONE w/ ONE Plus Family
In August 2018, T-Mobile introduced T-Mobile ONE w/ ONE Plus Family plan, which allows HD streaming and adds 20 GB of mobile hotspot at 4G LTE speeds, and Name ID.

As of June 2, 2019, the T-Mobile ONE and ONE w/ ONE Plus Family plans have been retired and replaced by the new Magenta plans.

T-Mobile ONE
In August 2016, T-Mobile introduced T-Mobile ONE. It will be the only rate plan offered in the future, with plans to gradually phase out Simple Choice. The plan has been criticized by the Electronic Frontier Foundation and others for potentially violating net neutrality rules and making previously included features paid extras.

As of June 2, 2019, the T-Mobile ONE and ONE w/ ONE Plus Family plans have been retired and replaced by the new Magenta plans.

T-Mobile Essentials
The T-Mobile Essentials plan provides customers unlimited talk, text, and data service at a lower price than a standard Magenta or Magenta Plus plan. However, the Essentials plan does not include taxes and fees as the Magenta and Magenta Plus plans do. It also allows T-Mobile to prioritize other customers over Essentials customers' data usage on the network at any time during network congestion or peak times.

Netflix On Us
T-Mobile offers many customers Netflix on Us, which covers the cost of a standard Netflix subscription. Customers can upgrade their subscription to Netflix's premium service for an additional cost, which will be added to the customer's T-Mobile bill.

Simple Choice
In March 2013, T-Mobile introduced a new streamlined plan, Simple Choice, for new customers. This is part of an initiative called Un-carrier which drops contracts, subsidized phones, overage fees for data, and early termination fees.

Capping unlimited data users
On August 31, 2015, T-Mobile announced it will ask users who abuse its unlimited on-smartphone data plan by violating T-Mobile's Terms & Conditions regarding tethering (which like unlimited on-smartphone data, remains unlimited, but offers a 14 GB high-speed allotment before throttling takes effect), by permanently removing user access to unlimited plans and migrating users to a tiered data plan. By doing so, all plans after a select amount of inclusive high-speed data, result in automatic throttled speeds, preventing unlimited high-speed tethering use and abuse of the network. T-Mobile stated that there are a small handful of users who abuse the tethering plan by altering device software and/or the use of an Android app that masks T-Mobile's ability monitoring whether data is on-smartphone, or through smartphone mobile hotspot (tethering) by mimicking all data as on-smartphone use, with some customers abusing the service by using as much as 2 TB per month, causing speed issues for all other customers.

InReach program
The InReach program provides a free cell phone and a limited number of voice minutes each month for low-income-eligible families (one per family) who do not use Lifeline services offered by any other phone or wireless company.  It is funded through the Universal Service Fund, but is only operational in a limited number of states and Puerto Rico.

Prepaid mobile phone & data

Ultra Mobile

Currently pending is T-Mobile's acquisition of Ultra Mobile which was announced on March 15, 2023.

Mint Mobile

Currently pending is T-Mobile's acquisition of Mint Mobile—a spinoff of Ultra Mobile—that was announced on March 15, 2023.

Tello Mobile

Founded in 2016, Tello Mobile now uses the T-Mobile network to provide MVNO talk, text, and data to its customers. Tello originally used the Sprint network, but transitioned to the T-Mobile network after the T-Mobile and Sprint merger.

Metro by T-Mobile

The former MetroPCS was taken over by T-Mobile in 2013, the new company formed T-Mobile US and currently continues to offer prepaid wireless services under the Metro by T-Mobile brand.

Assurance Wireless

The T-Mobile network has carried Assurance Wireless since the 2020 Sprint merger. The service is subsidized by the federal Lifeline Assistance program, a government benefit program supported by the federal Universal Service Fund. Low-income people who qualify for the services are provided a free phone, free monthly data and minutes, and unlimited texting.

Former prepaid services

GoSmart Mobile
GoSmart Mobile was a T-Mobile branded service that launched in beta on December 7, 2012, and became officially available nationwide on February 19, 2013. GoSmart offered no-contract SIM wireless services. GoSmart Mobile was sold to consumers through dealers who worked as independent contractors under their own company name. Such sellers are known as "Authorized Dealers" with either physical or online stores. In September 2016, T-Mobile sold the brand and 326,000 GoSmart Mobile customers to TracFone Wireless. The customers were reclassified as wholesale subscribers.

Television and streaming

TVision

On December 13, 2017, T-Mobile US announced its intent to acquire the IPTV provider Layer3 TV, which operates in Chicago and Washington, as the basis of its own subscription television service initially planned to launch in 2018. On April 10, 2019, T-Mobile officially announced the re-branding and re-launch of Layer3 TV as TVision Home The service mirrors the hardware, packaging, and pricing models of other linear television providers.

On October 27, 2020, T-Mobile US introduced over-the-top streaming services under the TVision branding. It consisted of several packages, including TVision Vibe (a lower-cost bundle focused on entertainment channels), TVision Live (network television, basic cable and sports networks, as well as cloud DVR), and TVision Channels (with standalone subscriptions for pay television services). TVision Home ceased operations on December 30, 2020.

On March 29, 2021, T-Mobile announced that TVision would be discontinued on April 29, 2021. The provider will instead offer promotional bundles with the third-party providers Philo and YouTube TV.

Financial services

Banking cards
On January 22, 2014, T-Mobile announced that it would expand its products into banking. T-Mobile would provide Visa card with banking features and a smartphone money management application with reduced-fee or zero-cost services for T-Mobile wireless customers. In addition, customers would have access to over 42,000 ATMs with no fees. In early 2016, T-Mobile decided to discontinue the banking cards. They can no longer be purchased at T-Mobile.

Online banking
In early 2019, T-Mobile released an online banking option called "T-Mobile Money".

Customer service

Team of Experts

In 2018, T-Mobile officially announced its new customer care concept called Team of Experts. The premise being customers never being transferred to another department. All representatives are trained in billing, payment arrangements, and cancellations when in the past each had their own separate department. In addition to being cross-trained, the Team of Experts, which consists of usually between 30 and 35 account reps, 4 to 6 technical support representatives, 4 supervisors overseeing the representatives, and one manager, are assigned specific markets, usually within the region the call center is in.

Awards
From as early as 2004, the company has captured multiple J. D. Power annual awards in the areas of retail sales satisfaction, wireless customer care, and overall customer satisfaction. In 2011, J. D. Power and Associates stated that T-Mobile retail stores achieved the highest ratings among major wireless carriers for customer satisfaction for the fourth consecutive year, performing particularly well in price and promotions. Also in 2011, J. D. Power and Associates ranked T-Mobile USA highest among major providers in wireless customer care for the second consecutive year.

On December 3, 2015, Consumer Reports named T-Mobile the number one American wireless service provider. The results combine data from customer service, voice quality, text messaging services, and data speeds.

On February 6, 2016, T-Mobile was awarded the JD Power Award for customer satisfaction in the full-service wireless category for the second year in a row. T-Mobile received the highest score ever in the wireless industry.

In 2019, T-Mobile was recognized as one of Fortune's Top 100 Companies To Work For, ranking #49.

Marketing

Jamie Lee Curtis was the spokesperson for T-Mobile USA's predecessor, VoiceStream Wireless, since 1998. VoiceStream's advertising slogan was: "Get more from life". During the transition to the T-Mobile brand, Jamie Lee Curtis continued as a spokesperson for a short time and the slogan was changed to "T-Mobile. Get More."
Starting in 2002, the company's spokesperson was Catherine Zeta-Jones who was the main figure in its branding strategy. As of September 2006, Zeta-Jones had officially been dropped as the "face" of the company for its advertising campaigns due to a corporate rebranding strategy. The company also relied on rapper Snoop Dogg as the spokesperson for its T-Mobile Sidekick in a series of commercials late in 2004, the company also released a series of Sidekick phones known as the D-Wade Edition for basketball player Dwyane Wade.

The company is also an official sponsor of Major League Baseball, the National Basketball Association, the NBA Rookie Challenge, Women's National Basketball Association, and the Overwatch League. In Puerto Rico, the company also sponsors the Puerto Rico Olympic Committee.

In late May 2009, Zeta-Jones was brought back as a company spokesperson to show customers how to pay less for their wireless plan in a new "Mobile Makeovers" advertising campaign that refers a customer to third-party comparison site BillShrink.com.

In late 2009, commercials for the T-Mobile MyTouch 3G featured the song "If You Want to Sing Out, Sing Out" by Cat Stevens and celebrities such as Chevy Chase, Molly Shannon, Dana Carvey, and Darrell Hammond. Another commercial with the same song performed by a different artist showed Wyclef Jean, Avril Lavigne, and Brad Paisley.

Carly Foulkes is the spokeswoman for the myTouch 4G in commercials that parody the Get a Mac campaign. The model is known for Rugby Ralph Lauren ads.
Although Foulkes is often identified with the color pink, T-Mobile actually has a color trademark for the color magenta, and markets itself using its corporate colors.
Virgin Mobile has, in turn, parodied the Carly Foulkes ads.

In September 2010, the company launched "Kids are free till 2012" for family lines.

On December 1, 2011, a group of 100 Chicago-area women, along with Carly Foulkes, were featured in a flash-mob style performance at Woodfield Mall in Schaumburg, Illinois, where the group, dressed in magenta dresses, sang and danced through the mall's atrium to their cover of (There's No Place Like) Home for the Holidays. The performance was filmed and edited into a holiday commercial, which was a success.

T-Mobile US has naming rights contracts with several prominent US sports venues. In 2016, the company signed a contract to place its name on a venue then nearing completion on the Las Vegas Strip. T-Mobile Arena became home to the Vegas Golden Knights of the NHL the following year. In 2018, with Safeco Insurance choosing not to renew its naming contract with Major League Baseball's Seattle Mariners to place its name on the team's stadium, T- Mobile US signed a similar deal, resulting in the former Safeco Field becoming T-Mobile Park on January 1, 2019. Most recently, the name of the main indoor arena in Kansas City, Missouri, changed from Sprint Center to T-Mobile Center following the two companies' 2020 merger. Additionally, T-Mobile US has naming rights for the Distrito T-Mobile, an entertainment and retail complex located next to the Puerto Rico Convention Center in San Juan, Puerto Rico.

Un-carrier movement
Starting in 2013, T-Mobile launched the Un-carrier marketing campaign. This movement introduced a slew of new tactics to offer consumers cheaper rate plans, cheaper global coverage, and several other benefits. T-Mobile CEO John Legere laid out an "Un-Carrier manifesto" highlighting the approach and goals he wanted the company to pursue. One popular Un-carrier move features T-Mobile Tuesdays, where customers are offered a variety of free products and also able to win prizes. The most recent Un-carrier campaign is titled "T-Mobile One". This is a new family plan offering, replacing all previous plans and is an all-inclusive unlimited plan, giving unlimited talk, text, and data. The only caveat being a video streaming on any device is limited to 480p resolution. CEO John Legere in an interview said "The biggest pain point that a million customers told me about is that they hate data buckets. And we had such success with Binge On that we wanted to turn our company into somebody that's selling a monthly subscription to the internet, all in, unlimited." As of October 7, 2016, about a quarter of the overall account numbers have moved over to T-Mobile One, and about three-quarters of new postpaid accounts are activating on T-Mobile One.

Labor relations
T-Mobile US employees and two labor unions have led multiple unionization attempts beginning as early as 2001.

Formation of TU
Hundreds of T-Mobile employees, with the backing of the Communications Workers of America (CWA) and the German union ver.di, have come together as TU to gain representation at T-Mobile. In July 2011, technicians in Connecticut, voted for representation by the Communications Workers of America-TU. On September 25, 2013, MetroPCS workers in Harlem, NY, voted for a union voice and representation by CWA-TU.

2009 coordinated organizing effort

In 2008, the CWA and ver.di launched a coordinated effort to unionize company employees. A spokesman for the CWA called on the company to stop resisting mobilization efforts and allow company employees to unionize as German employees of T-Mobile USA's parent company, DT, have done. In response, the company released an employee satisfaction study showing that more than seventy percent of the company's 40,000 workers were "very satisfied" with their jobs. Through a spokesman, the company stated, "Despite the Communication Workers of America's periodic organizing efforts for more than nine years, no group of T-Mobile employees has ever chosen to be represented by a union. While our company is always striving to find ways to improve, year after year, employees continue to view T-Mobile as a good place to work where they have no need for, or interest in, a union."

Political pressure
In 2009, a number of politicians, in one case acting after lobbying efforts by CWA union activists, wrote letters to René Obermann, DT's chief executive officer, in an effort to influence T-Mobile USA's labor practices in the U.S.

In a March 13, 2009, letter, U.S. Senator John Kerry (D-MA) asked "why the company's approach to labor rights are different in Germany than in the United States". In an April 30, 2010, letter sent after lobbying by Communications Workers of America activists, 26 Democratic members of Congress called on DT to protect and respect workers' rights in the U.S. A separate July 1, 2010, letter from seven Republicans addressed the same issue. On August 10, 2010, U.S. Senator Bob Casey (D-PA) released a statement in support of the worker's efforts to organize a union at the company. In a letter, dated September 21, 2010, fifteen Californian Members of Congress urged Obermann to take action and implement fair and equitable labor relations.

In a November 5, 2009, letter, Thomas DiNapoli, New York State Comptroller and Trustee of the New York State Common Retirement Fund, stated concerns about "the potential impact on the value of T-Mobile that may result from a disenfranchised workforce and the associated negative publicity that may impact T-Mobile's profitability."

Reports

On December 9, 2009, the non-profit organization American Rights at Work published a report written by Prof. John Logan, Director of Labor Studies at San Francisco State University, titled "Lowering the Bar or Setting the Standard? Deutsche Telekom's U.S. Labor Practices". The report details behavior by the company that the author perceives as anti-union including dissemination of anti-union materials, intimidation and threats directed at pro-union workers, "captive audience meetings" and the retention of anti-union specialists. In the report, which is based on documents from the National Labor Relations Board, internal company memos and handbooks, and interviews with workers, Logan asserts that the company engaged in a systematic campaign to prevent employees from forming a union and that DT was guilty of operating by a double standard. He claims that Deutsche Telekom respects workers' rights in Germany, where it cooperates closely with unions, but mistreats workers in the United States and interferes with their right to organize.

On September 2, 2010, Human Rights Watch released a report written by Lance Compa titled "A Strange Case: Violations of Workers' Freedom of Association in the United States by European Multinational Corporations". The report concludes that "company policy has translated into practices that leave the workforce fearful about even seeking union representation." DT proclaims its adherence to international labor law and standards that are embodied in German domestic laws. But HRW found that "T-Mobile USA's harsh opposition to workers' freedom of association in the United States betrays Deutsche Telekom's purported commitment to social responsibility, impedes constructive dialogue with employee representatives, and in several cases, has violated ILO and OECD labor and human rights standards".

Labor Related Awards
T-Mobile has received multiple workplace awards. T-Mobile received a score of 100 on the Disability Equality Index (DEI), which measures disability inclusion. They were also named the Best Place to Work for LGBT Equality by the Human Rights Campaign for four consecutive years. T-Mobile was also awarded a Designation for the top 100 Military Friendly Employer by Military Friendly in 2017 for the tenth time. It was recognized as one of the World's Most Ethical Companies by the Ethisphere Institute for the ninth year in a row. In addition to national awards, T-Mobile has also won local awards in many locations, including the best place to work in Albuquerque, New Mexico, and Wichita, Kansas, where the company has some call centers located. On February 16, 2018 Fortune announced their 100 best companies to work for, naming T-Mobile 86th. On July 24, 2018, Forbes ranked T-Mobile 182nd on their top 300 Best Places to Work for Women list.

Controversies

Sidekick data outage

On October 1, 2009, some users of Microsoft's Sidekick handset temporarily lost personal data, including contacts, notes, and calendars. On October 8, most data services were restored to users.  The company and Microsoft announced on October 10 that Sidekick device data "almost certainly has been lost as a result of a server failure at Microsoft/Danger." On October 15, Microsoft said it had been able to recover most or all data and would begin to restore it.

Network outages
On November 9, 2009, some of the company's subscribers temporarily lost the ability to send and receive calls and text messages for several hours. The company confirmed the outage via Twitter. The company stated that approximately five percent of its subscribers had been affected. It claimed that the problem was caused by a system software error.

On May 8, 2018, subscribers in Houston, Texas, experienced a four-hour service interruption caused by damage to a fiber-optic cable.

On June 15, 2020, subscribers across the United States suffered a service outage (primarily voice and text) due to routing issues.

On February 13, 2023, T-Mobile users across the United States experienced widespread network outages. The company quickly responded that they were looking to address the disruption that caused the cellular service outage.

Misrepresentation as 4G
In 2010, T-Mobile began marketing both its HSPA and HSPA+ services as "4G". Media outlets called this branding deceptive.

After the ITU expanded its definition of 4G to include HSPA+, T-Mobile continued to market standard HSPA devices and service as 4G. Not only do these HSPA (non-Evolved) devices continue to not meet 4G standards, they are incapable of operating at 4G speeds. Concerns were also displayed over the possibility of confusion when actual LTE networks were deployed.

Information security
Nicolas Jacobsen was charged with intruding into the company's internal network in January 2005. Reports indicated that for about a year Jacobsen had access to customer passwords, e-mail, address books, Social Security numbers, birth dates, and Sidekick photos. Affected customers included members of the United States Secret Service. Secret Service informant identified Jacobsen as part of "Operation Firewall" which provided evidence that Jacobsen had attempted to sell customer information to others for identity theft. T-Mobile USA and the Secret Service did not elaborate on the methods Jacobsen used to gain access but sources close to the case indicated that Jacobsen exploited an unpatched flaw in the Oracle WebLogic Server application software used by the company. Additional SQL injection vulnerabilities with the company's web site were reported by Jack Koziol of the InfoSec Institute.

T-Mobile offers access to voicemail without the input of a password by default. Parties acting in bad faith may be able to access such voice mailboxes via Caller ID spoofing. To avoid this possibility, T-Mobile recommends that all customers password-protect their mailboxes, but still offers the no password configuration by default due to customer demand.

On June 6, 2009, a message posted from an email account "pwnmobile_at_Safe-mail.net" to the Full Disclosure mailing list claimed that the company's network had been breached and showed sample data. The sender offered "databases, confidential documents, scripts and programs from their servers, financial documents up to 2009" to the highest bidder. On June 9, the company issued a statement confirming the breach but stating that customer data was safe. It claimed to have identified the source document for the sample data and believe it was not obtained by hacking. A later statement claimed that there was not any evidence of a breach.

Privacy and surveillance
T-Mobile USA received a portion of the 1.3 million largely warrantless law enforcement requests for subscriber information (including text messages and phone location data) made in 2011, but refused to state how many requests it received. It did say that in the last decade, the number of requests have increased by 12 to 16 percent annually.

Data retention policies
According to T-Mobile's privacy policy highlights, "Retention and Disposal", information is retained for as long as there is business or tax need or as applicable laws, regulations, or government orders require. T-Mobile notes that it disposes of Personal Information,  uses reasonable procedures designed to erase or render it unreadable (for example, shredding documents and wiping electronic media).

In 2010, the Department of Justice (DOJ) released a document entitled, "Retention Periods of Major Cellular Providers," to advise law enforcement agents seeking to obtain cell phone records. This document was uncovered by the ACLU's coordinated records request on cell phone location tracking by police. Notably, the document showed that T-Mobile subscriber information was retained for 5 years and call detail records were kept for 2 years (prepaid) and 5 years (postpaid).

In 2013, Massachusetts Sen. Edward Markey revealed responses from the top four U.S. wireless providers as well as U.S. Cellular, C Spire, and Cricket/Leap Wireless, to his inquiry regarding user information disclosed to law enforcement officials. The following was T-Mobile's response regarding data retention: T-Mobile US retains customers' historic cell site information and cell tower dump information (180 days); call details records (7–10 years); text message content, data requests, and geo-location data not stored; voicemail content (up to 21 days); subscriber information (6 years after the account is closed).

2021 data breach
On August 16, 2021, T-Mobile confirmed that the company had been subject to a data breach but declined to say whether any customers' personal information was accessed or how widespread the damage was. The company acknowledged the breach after hackers told Vice the day prior that they were selling "full customer info" obtained from T-Mobile servers.

On August 18, 2021, T-Mobile provided an update on the latest findings regarding the data breach. According to the preliminary analysis, the hackers were able to obtain the records more than 40 million former and prospective customers that had applied for credit along with 7.8 million existing postpaid customers. T-Mobile has confirmed that the data collected by the hackers included sensitive personal information, such as the first and last names, birthdates, driver's license/ID numbers, and Social Security numbers, but were unable to access phone numbers, account numbers, PINs or passwords. T-Mobile offered two years of free identity protection services and also recommended for customers to change their PIN as soon as possible. No Metro by T-Mobile, former Sprint prepaid, or Boost Mobile customers were affected by the breach.

It was reported on August 23, 2021 that T-Mobile was subject to multiple class-action lawsuits that were filed in federal court as the number of both current and former customers impacted by the cyberattack grew. One of the lawsuits accused T-Mobile of putting plaintiffs as well as members of the class-action to "considerable risk" due to the failure to adequately protect its customers as a result of negligence. The second lawsuit alleged that attack victims spent as much as 1,000 hours to address the privacy concerns stemming from the attack which included reviewing financial and credit statements for evidence of unauthorized activity.

On August 24, 2021, it was announced that T-Mobile Business customers were affected by the data breach according to T-Mobile for Business information site which stated that the exact business and personal information that was accessed varies by business and individual. The company determined that the types data that impacted businesses included the business's name, federal tax ID, business address, contact name, and business phone number, as well as the personal information stated in the above paragraphs; there was no indication that business or personal financial information, including credit or debit card information, account passwords or PINs were included in the data breach.

On August 26, 2021, self-reputed hacker John Binns claimed responsibility for the attack and offered an interview on how he was able to access T-Mobile's servers. He said that he used a readily available tool to locate an exposed router and that it took him a week to penetrate the customer data stored in a T-Mobile data center near East Wenatchee, Washington. He also provided evidence to support his claim of being responsible for the attack and that he stole the data to create "noise" and get attention. The Wall Street Journal asked T-Mobile about the claims but they declined to comment. The total number of customers affected, despite previous reports, was 76.6 million.

On September 6, 2021, T-Mobile US customers filed class action lawsuits accusing the company of negligence after the data breach incident. Three lawsuits have been filed in district court and all demand jury trials. Two of the complaints accuse T-Mobile of violating the US Federal Trade Commission (FTC) Act of 1914, which prohibits companies from engaging in "unfair or deceptive" activities, which includes companies failing to maintain appropriate security measures to safeguard customer information. In another filing, the plaintiff noted that the FTC provided cybersecurity guidelines advising companies not to maintain personally identifiable information "longer than is needed for authorisation of a transaction". Another class action suit accuses T-Mobile of violating the California Consumer Privacy Act, which assigns specific penalties to companies which allow unauthorised access to their customers' data.

It was subsequently reported that T-Mobile attempted to stop the sharing of the stolen data at the time of the incident by secretly paying the hackers over $200,000 through an intermediary. The plan failed and the stolen data remained available for sale.

Other cybersecurity incidents
Including the widely-reported 2021 data breach, T-Mobile has had no less than twelve cybersecurity-related incidents since 2009. At least two data breaches have occurred in 2023, marking a total of nine breaches since 2018. Some of these breaches occurred even after T-Mobile spent $150 million on cybersecurity in response to the 2021 data breach.

See also

 List of companies based in Bellevue, Washington
 List of United States wireless communications service providers
 List of mobile network operators of the Americas

References

External links

 Deutsche Telekom AG website
 T-Mobile's 2021 data breach website

Mobile phone companies of the United States
Telecommunications companies of the United States
Wi-Fi providers
Companies based in Bellevue, Washington
Deutsche Telekom
Softbank portfolio companies
American subsidiaries of foreign companies
Telecommunications companies established in 1994
Retail companies established in 1994
American companies established in 1994
1994 establishments in Washington (state)
2013 initial public offerings

T-Mobile US


Dual-polarization interferometry (DPI) is an analytical technique that probes molecular layers adsorbed to the surface of a waveguide using the evanescent wave of a laser beam. It is used to measure the conformational change in proteins, or other biomolecules, as they function (referred to as the conformation activity relationship).

Instrumentation
DPI focuses laser light into two waveguides. One of these functions as the "sensing" waveguide having an exposed surface while the second one functions to maintain a reference beam. A two-dimensional interference pattern is formed in the far field by combining the light passing through the two waveguides. The DPI technique rotates the polarization of the laser, to alternately excite two polarization modes of the waveguides. Measurement of the interferogram for both polarizations allows both the refractive index and the thickness of the adsorbed layer to be calculated. The polarization can be switched rapidly, allowing real-time measurements of chemical reactions taking place on a chip surface in a flow-through system. These measurements can be used to infer conformational information about the molecular interactions taking place, as the molecule size (from the layer thickness) and the fold density (from the RI) change. DPI is typically used to characterize biochemical interactions by quantifying any conformational change at the same time as measuring reaction rates, affinities and thermodynamics.

The technique is quantitative and real-time (10 Hz) with a dimensional resolution of 0.01 nm.

Extensions of dual-polarization interferometry also exist, namely multiple pathlength dual-polarization interferometry (MPL-DPI) and absorption enhanced DPI. In MPL-DPI quantification of both layer thickness and refractive index (density) and therefore mass per unit area can be made for in situ and ex-situ coated films, where normal DPI can only calculate film properties if the interferogram is constantly monitored. Absorption enhanced DPI (AE-DPI) is used to separate the mass of different molecules on the surface, exploiting the absorption of one of the molecular species compared to the other species on the surface.

Applications
A novel application for dual-polarization interferometry emerged in 2008, where the intensity of light passing through the waveguide is extinguished in the presence of crystal growth. This has allowed the very earliest stages in protein crystal nucleation to be monitored. Later versions of dual-polarization interferometers also have the capability to quantify the order and disruption in birefringent thin films. This has been used, for example, to study the formation of lipid bilayers and their interaction with membrane proteins.

References

Further reading

Biosensors
Interferometry
Protein–protein interaction assays
Protein methods
Polyelectrolytes
Scientific instruments
Scientific equipment

Dual-polarization interferometry


Child labour in India is when Indian children work for money, on a part or full-time basis....

The practice deprives children of their childhood, and is harmful to their physical and mental development. Various things lead to children working. Poverty, lack of good schools and informal work places may be blamed.

The 1998 national census of India estimated the total number of child labour, aged 4–15, to be at 12.6 million, out of a total child population of 253 million in 5-14 age group. The 2011 national census of India found the total number of child labour, aged 5–14, to be at 4.35 million, and the total child population to be 259.64 million in that age group.

The child labour problem is not unique to India; worldwide, about 217 million children work, many full-time.

References

Child labour

Child labour in India


Margaret of Baden (1431 – 24 October 1457) was a Margravine of Baden by birth and by marriage Margravine of Brandenburg-Ansbach and Brandenburg-Kulmbach.  She was the daughter of Jacob, Margrave of Baden-Baden, and his wife Catherine of Lorraine.

In 1446, Margaret married Albert of Brandenburg, the future Albert III Achilles, Elector of Brandenburg, in Heilsbronn.  Margaret died before he succeeded to the Electorate of Brandenburg, thus never served as Electress. Their marriage produced three sons and three daughters:
 Ursula (1450–1508)
 married in 1467 Duke Henry I of Münsterberg-Oels (1448-1498)
 Elisabeth (1451–1524)
 married in 1467 Duke Eberhard II of Württemberg (1447-1504)
 Margaret (1453–1509), abbess of the Poor Clares convent at Hof from 1476
 John Cicero (1455–1499), Elector of Brandenburg

Margaret died in Ansbach in 1457 shortly after her husband acquired the Margraviate of Brandenburg-Kulmbach.

|-

Margravines of Brandenburg-Ansbach
House of Hohenzollern
1431 births
1457 deaths
15th-century German people
15th-century German women
House of Zähringen
Daughters of monarchs

Margaret of Baden


The 1962 LOT Vickers Viscount Warsaw crash occurred on 19 December 1962 when a Vickers Viscount 804, operated by LOT Polish Airlines on a flight from Brussels to Warsaw, crashed on landing. All passengers and crew died.

The plane was returning from Brussels, and had a mid-way landing in Berlin from where it took off at 5:55 pm. While on approach on runway 33 in Warsaw at 7:30 pm the crew received landing clearance. 46 seconds later the plane crashed and burned 1335 meters from the threshold.

All 33 people aboard died – the crew of 5 and 28 passengers. Among the victims was Heinz Rauch, head of the East German statistical service, along with his wife and two children

The Chief Committee of Aircraft Accident Investigation stated that at the time of the accident the plane was configured for landing (flaps set and landing gear lowered). It also stated there was no explosion mid-air and all damage was a result of the crash. The plane was landing in harsh, Winter weather conditions, with dense near-ground fog, 6/8 overcast, fractostratus clouds at 250 meters, 7-km visibility and temperature of 5 degrees below 0.

One of the probable causes of stalling due to low speed was attributed to turboprop engines features which change the propellers pitch during acceleration. Hence sudden throttle increase is not recommended. Such a maneuver was probably executed by the Captain who was accustomed to flying piston engine aircraft in which such maneuvers are allowed. The Vickers Viscount 804 was one of three recently bought from British United Airways in England.  On LOT's roster the airliner had logged only 84 flight hours.

Official accident causes:
 Crew error
 Crew training errors

There is a possibility that one of the NDB during approach was broken unbeknown to the crew.

References

 Aviation Safety Network accident description
 ICAO Accident Digest No 14 Volume II Circular 71-AN/63, no.27 (str. 147/148) – report extract

Aviation accidents and incidents in Poland
Aviation accidents and incidents in 1962
1962 in Poland
LOT Polish Airlines accidents and incidents
December 1962 events in Europe
Accidents and incidents involving the Vickers Viscount
1962 disasters in Poland

1962 LOT Vickers Viscount Warsaw crash


Coon Rapids is a city in Carroll and Guthrie counties in the U.S. state of Iowa. The population was 1,300 at the 2020 census, which is a decrease of 5 from the 2000. The small portion of Coon Rapids that lies in Guthrie County is part of the Des Moines–West Des Moines Metropolitan Statistical Area.

History

Wheeling and dealing in public land marked the emergence of Carroll county. The county seat, Carrollton, was built on land given by two Fort Des Moines speculators. Two savvy Carrollton residents, Crocket Ribble and Jacob Cretsinger decided to try their hand in real estate. They purchased land along the Middle Raccoon River, built a saw and grist mill and went into business in 1864. Between the impact of the Civil War and later national panics, frontier settlement slowed down. However, the partners were able to establish a post office, named Coon Rapids; become a stop on stage coach service to Sioux City. Returning civil war veterans, William Minnich and his brother in law, Michael Shettler saw potential in the hamlet. After purchasing land, they submitted a plat for the village of Coon Rapids and built what would become a store-hotel and home for the Shettler family. Minnich maintained his farm in adjoining Guthrie County. Between 1870 and 1880, the hamlet grew as former farmers became merchants and tradesmen and newcomers came to the area. In addition to the Mill, the town had several general stores offering an array of goods, a hardware store, implement dealer and the all important real estate agent.

When the Chicago, St Paul and Milwaukee started to build a rail line about a half mile south west of the hamlet, they established a rough and tumble camp for their workers, many of whom were accompanied by their families. The railroad project provided jobs and good money for local boys and newcomers. A boom began. Between 1880 and 1886, merchants in the village of coon rapids literally moved their buildings into what the railroad had platted as a town. Main street slowly became lined with business houses and homes and the area between the old and new towns slowly was transformed into a residential area. The editor of the newly established newspaper, Coon Rapids Enterprise, bemoaned the lawlessness and intemperate behavior found in the new town. Selling liquor seemed to be the primary business! However, the town grew, nearly doubling in population and the new commercial center by the railroad expanded with a variety of new and old businesses. 1886 could have marked the end of Coon Rapids. A tornado ripped across western Iowa and Coon Rapids was in its path. The eastern part of town was demolished. Fortunately, only two in town had died, but the property damage within town and along the tornadoes route was immense. Help poured in from around the United States and the town rebuilt. However, this wooden frontier community was vulnerable to fire. Between 1887 and 1894, a multitude of fires occurred some caused by arson, others by lightning, and others the result of cinders from flues
igniting dry, shingled roofs.

During the late 19th century, Coon Rapids developed a modern, fireproof commercial district made up of brick buildings, exhibiting a variety of Victorian facades. Now this small brick city began to the amenities of urban life such as theater productions, roller skating, bowling, billiards, restaurants and a variety of shops and services, dray lines and livery barns. There were wooden sidewalks and street lights. A night watch and sheriff kept night time lawlessness in control and limited racing down Main street. Now there were community celebrations such as July 4 and Decoration Day for both town and rural folk . A town baseball team was another attraction. The town became a service center for a growing agricultural economy. Community wide events such as Decoration Day, Fourth of July celebration, and school graduations. Church and club celebrations became part of community life and served to integrate community and countryside.

In response to the increased town and rural population and agricultural specialization, Coon Rapids saw the appearance of service industries to support the changing farm economy. There were carpenters specializing in farm building construction, well diggers, tiling and drainage concerns, dealers in cement and other types of fencing, a creamery to support the burgeoning dairy and poultry industry. By the early twentieth century, Coon Rapids was the dominant trading center between Perry and Manning. The downtown was filled with two and three storey brick buildings and offered an array of shops, services, and amenities such as an opera house, bowling alley, restaurants, a hotel and other amusements. From a simple market and trading point, Coon Rapids had become the economic, social, recreational and service center for the four county areas. It continued in this role despite the fall in farm values in the late teens and Great Depression of the 1930s.

The entrepreneurial tradition that marks Coon Rapids was expressed in the twentieth century by businesses that served the diverse agricultural economy of the area. These included major grain dealers who maintained elevators in town, lumber men, implement dealers, a creamery and related produce stations, extensive poultry operations, a stock yard and sale barn. Of particular importance to the town's 20th century life was the emergence of the hybrid corn business.

Industrial agriculture transformed the Midwest in the post WW II era. Economies of scale shifted centers of production, for example, the poultry business became concentrated in the southeastern United States, the size of farms increased, corporate rather than individual farming operations became the norm. For Coon Rapids this had varied impacts. Garst and Thomas Seed had expanded into an international concern by the mid-1950s offering local employment opportunities . Garst and Thomas expanded physically, literally taking over many of the downtown buildings in Coon Rapids, converting them to laboratory and office space. The city's residential areas grew during the late twentieth century, largely due to the employment offered by Garst and Thomas. Although the range and variety of downtown shops and businesses changed between 1950 and the farm crisis of the 1980s, the town maintained basic services such as a grocery store, hardware store, real estate and insurance agencies, banks, lumber yard, and agricultural service businesses. In September 1959, Coon Rapids played a role in promoting détente between the United States and the Soviet Union, when area resident Roswell Garst hosted Soviet premier Nikita Khrushchev on his farm.

Twenty-first-century Coon Rapids lives on the tenacity and commitment of its residents. Syngenta, POET Biorefining, ET video and other local industries remain strong in large part to a dedicated and productive local workforce. Returning natives have energized the town. The Whiterock Conservancy, an innovation in eco-tourism, promises greater interest in Coon Rapids through its opportunities for year-round outdoor activities. A small but thriving arts and crafts community sponsors an annual art fair, offers classes, and sells paintings, baskets, clocks, pottery, stained glass, photographs, handmade furniture and wooden pens. In addition, a local musician has initiated a series of house concerts which are held in a variety of venues. City leaders and residents continue to work to improve the quality of life in the community with the expectation Coon Rapids will remain a viable rural Iowa town far into the future.

Geography

Coon Rapids is located along the Middle Raccoon River.

According to the United States Census Bureau, the city has a total area of , all land.

Demographics

2010 census
As of the census of 2010, there were 1,305 people, 550 households, and 337 families residing in the city. The population density was . There were 613 housing units at an average density of . The racial makeup of the city was 97.7% White, 0.1% African American, 0.1% Native American, 1.4% from other races, and 0.8% from two or more races. Hispanic or Latino of any race were 3.3% of the population.

There were 550 households, of which 28.9% had children under the age of 18 living with them, 49.1% were married couples living together, 8.5% had a female householder with no husband present, 3.6% had a male householder with no wife present, and 38.7% were non-families. 35.3% of all households were made up of individuals, and 18.6% had someone living alone who was 65 years of age or older. The average household size was 2.30 and the average family size was 2.97.

The median age in the city was 41.3 years. 25.9% of residents were under the age of 18; 5.1% were between the ages of 18 and 24; 21.8% were from 25 to 44; 23.7% were from 45 to 64; and 23.4% were 65 years of age or older. The gender makeup of the city was 47.0% male and 53.0% female.

2000 census
As of the census of 2000, there were 1,305 people, 543 households, and 346 families residing in the city. The population density was . There were 571 housing units at an average density of . The racial makeup of the city was 99.16% White, 0.61% African American, 0.15% Native American, and 0.08% from two or more races. Hispanic or Latino of any race were 1.76% of the population.

There were 543 households, out of which 27.8% had children under the age of 18 living with them, 53.6% were married couples living together, 7.9% had a female householder with no husband present, and 36.1% were non-families. 33.9% of all households were made up of individuals, and 19.7% had someone living alone who was 65 years of age or older. The average household size was 2.31 and the average family size was 2.95.

Age spread: 23.0% under the age of 18, 7.0% from 18 to 24, 23.0% from 25 to 44, 21.6% from 45 to 64, and 25.8% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 89.7 males. For every 100 females age 18 and over, there were 83.4 males.

The median income for a household in the city was $32,951, and the median income for a family was $39,800. Males had a median income of $29,018 versus $22,167 for females. The per capita income for the city was $16,765. About 6.8% of families and 9.1% of the population were below the poverty line, including 13.7% of those under age 18 and 7.7% of those age 67 or over.

Education
It is in the Coon Rapids–Bayard Community School District. The district was established on July 1, 1988, by the merger of the Bayard and Coon Rapids school districts.

Iowa Great Place
In October 2005, Coon Rapids-Whiterock area was elected a "Great Place" of Iowa for its rich history and resources, and creative future vision. The Great Places program, launched by Governor Tom Vilsack and implemented by the Department of Cultural Affairs, aimed to concentrate state agency resources on high-potential communities.

The local Great Place committee represents an alliance between the nonprofit Whiterock Conservancy, the City of Coon Rapids, and the Coon Rapids Development Group. Whiterock Conservancy is an Iowan nonprofit organized in late 2004 to administer a  private conservation land donation from the Garst family of Coon Rapids.  Its goals are environmental restoration, sustainable agriculture, and low-impact public use and education.

The first three Iowa Great Places (Coon Rapids, Clinton and Sioux City) were each awarded $1 million in seed money by the Iowa legislature. In September 2007, Coon Rapids was also awarded a $1.7 million Vision Iowa grant.  The Coon Rapids Great Place Program combines natural resource restoration with trails, public park development, elder care, diversity, historic preservation, microenterprise support, and tourism marketing.

Notable people

David Garst (1926–2006) President of Garst Seed Company Worked for different presidential administrations
Roswell Garst (1898–1977) Internationally prominent farmer and hosted Nikita Khrushchev at his farm
Warren Garst (1850–1924) Nineteenth governor of Iowa
Jay King "Babe" Towne (1880–1938) MLB played for the winning 1906 World Series team the Chicago White Sox

See also

 Roswell and Elizabeth Garst Farmstead Historic District
 Whiterock Conservancy
 Krushchev in Iowa Trail

References

External links

Coon Rapids, Iowa
Coon Rapids Tourism Guide
City-Data Comprehensive Statistical Data and more about Coon Rapids

Cities in Carroll County, Iowa
Cities in Guthrie County, Iowa
Cities in Iowa
Des Moines metropolitan area
Populated places established in 1864
1864 establishments in Iowa

Coon Rapids, Iowa


A labour camp, labor camp or work camp is a simplified prison in which inmates are forced to do hard labor, usually as punishment for crime. Instead of prison cells, labor camp inmates are usually housed in barracks. Soviet gulags and Nazi concentration camps are some examples. Conditions at labor camps tend to be extremely harsh.
Prisons

Labour camp


St. John African Methodist Episcopal Church was the first church for African Americans in Nebraska, organized in North Omaha in 1867. It is located at 2402 North 22nd Street in the Near North Side neighborhood. The building is listed on the National Register of Historic Places. The building was constructed in the center of Omaha's North Side in the Prairie School architecture style. Prairie School architecture is rare, and this architectural gem in urban Nebraska is particularly unusual for being designed and built in the 1920s, after the Prairie Style's rapid loss of popularity beginning after 1914.

About
Organized in the fall of 1865, the first minister of St. John was Rev. W. T. Osborne, who was also the first African American minister in Nebraska. The first meetings being held at a private residence on Capitol Avenue and Ninth Street in present-day downtown Omaha. After worshiping for a short time on Harney Street, the church moved to Douglas and Fifteenth Streets until the summer of 1865. That year a lot was purchased on the corner of Eighteenth and Webster Streets in Near North Omaha. The original church was built for $1,000.

The longest standing member of the church was Mrs. Eliza Turner, who until her death in 1938 regularly attended St. John's for seventy years. Today St. John hosts a thriving congregation, and the church serves in a variety of capacities to the surrounding community.

Pastors
Rev. J. H. Hubbard, 1866 to 1868
Rev. W. B. Ousley, 1868 to 1869
W. L. Harrod, 1869 to 1870
William Sexton, 1870 to 1871
G. W. Gaines, 1871 to 1873
J. W. Braxton, 1873 to 1875
B. F. Watson, 1875 to 1876
J. A. Fouche, 1876 to 1878

Architecture

St. John's has been housed in three different churches. The second church was located at North 25th and Grant Streets, and was notably designed by Omaha's first African American architect, Clarence W. Wigington, which was built around the turn of the century.

When the congregation outgrew that building, they located a new place to build at 2402 North 22nd Street, St. John A.M.E. Church building was designed by local architect Frederick S. Stott in 1921 in the Prairie School style. In 1947 an auditorium was added, and additional rooms were finished in 1956. The building is remarkable for its reflection of the progressive attitude of its congregation at a time when traditional values in religious architecture were prevalent. The building is recognized as an important contribution to the Prairie School style, and was added to the National Register of Historic Places in May 1980.

Notable members

St. John's has been host to several members who are notable in local and national history. They include:
 Ophelia Clenlans, civil rights leader in Omaha
 Harrison J. Pinkett, the first University trained lawyer in Nebraska and a civil rights leader in Omaha
 W. H. C. Stephenson, a doctor and civil rights leader in Omaha

See also
History of North Omaha, Nebraska
Architecture of North Omaha, Nebraska
Black church
 List of churches in Omaha, Nebraska

References

External links
St. John AME webpage on the official African Methodist Episcopal Church website.
Modern photo

20th-century Methodist church buildings in the United States
African-American history in Omaha, Nebraska
African Methodist Episcopal churches
Churches in Omaha, Nebraska
Clarence W. Wigington church buildings
History of North Omaha, Nebraska
Landmarks in North Omaha, Nebraska
Methodist churches in Nebraska
19th-century Methodist church buildings in the United States
National Register of Historic Places in Omaha, Nebraska
Prairie School architecture in Nebraska
Churches on the National Register of Historic Places in Nebraska
Churches completed in 1921
Religious organizations established in 1865
1865 establishments in Nebraska Territory

St. John African Methodist Episcopal Church (Omaha, Nebraska)


Cuddles may refer to:

As a nickname:
Jamie Cudmore (born 1978), Canadian rugby union player
Cadel Evans (born 1977), Australian cyclist
Cuddles Marshall (1925-2007), American Major League Baseball relief pitcher
S. Z. Sakall (1883-1955), Hungarian-born Hollywood character actor
Greg Welts, former member of the American heavy metal band Slipknot (1997-1998)

Fictional characters:
Cuddles, in the UK comic The Dandy - see Cuddles and Dimples
Cuddles (Happy Tree Friends), a rabbit in the American flash cartoon Happy Tree Friends
Cuddles the comfort doll, in the Canadian television series Puppets Who Kill
Cuddles the Monkey, a puppet operated and voiced by ventriloquist Keith Harris

Nicknames

Cuddles


Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a size ratio called optical magnification. When this number is less than one, it refers to a reduction in size, sometimes called de-magnification.

Typically, magnification is related to scaling up visuals or images to be able to see more detail, increasing resolution, using microscope, printing techniques, or digital processing. In all cases, the magnification of the image does not change the perspective of the image.

Examples of magnification
Some optical instruments provide visual aid by magnifying small or distant subjects.

 A magnifying glass, which uses a positive (convex) lens to make things look bigger by allowing the user to hold them closer to their eye.
 A telescope, which uses its large objective lens or primary mirror to create an image of a distant object and then allows the user to examine the image closely with a smaller eyepiece lens, thus making the object look larger.
 A microscope, which makes a small object appear as a much larger image at a comfortable distance for viewing. A microscope is similar in layout to a telescope except that the object being viewed is close to the objective, which is usually much smaller than the eyepiece.
 A slide projector, which projects a large image of a small slide on a screen. A photographic enlarger is similar.
 A zoom lens, a system of camera lens elements for which the focal length and angle of view can be varied.

Size ratio (optical magnification)
Optical magnification is the ratio between the apparent size of an object (or its size in an image) and its true size, and thus it is a dimensionless number. Optical magnification is sometimes referred to as "power" (for example "10× power"), although this can lead to confusion with optical power.

Linear or transverse magnification
For real images, such as images projected on a screen, size means a linear dimension (measured, for example, in millimeters or inches).

Angular magnification
For optical instruments with an eyepiece, the linear dimension of the image seen in the eyepiece (virtual image at infinite distance) cannot be given, thus size means the angle subtended by the object at the focal point (angular size). Strictly speaking, one should take the tangent of that angle (in practice, this makes a difference only if the angle is larger than a few degrees). Thus, angular magnification is given by:

where  is the angle subtended by the object at the front focal point of the objective and  is the angle subtended by the image at the rear focal point of the eyepiece.

For example, the mean angular size of the Moon's disk as viewed from Earth's surface is about 0.52°. Thus, through binoculars with 10× magnification, the Moon appears to subtend an angle of about 5.2°.

By convention, for magnifying glasses and optical microscopes, where the size of the object is a linear dimension and the apparent size is an angle, the magnification is the ratio between the apparent (angular) size as seen in the eyepiece and the angular size of the object when placed at the conventional closest distance of distinct vision:  from the eye.

By instrument

Single lens
The linear magnification of a thin lens is

where  is the focal length and  is the distance from the lens to the object. For real images,  is negative and the image is inverted. For virtual images,  is positive and the image is upright.

With  being the distance from the lens to the image,  the height of the image and  the height of the object, the magnification can also be written as:

Note again that a negative magnification implies an inverted image.

Photography
The image recorded by a photographic film or image sensor is always a real image and is usually inverted. When measuring the height of an inverted image using the cartesian sign convention (where the x-axis is the optical axis) the value for  will be negative, and as a result  will also be negative. However, the traditional sign convention used in photography is "real is positive, virtual is negative". Therefore, in photography: Object height and distance are always  and positive. When the focal length is positive the image's height, distance and magnification are  and positive. Only if the focal length is negative, the image's height, distance and magnification are  and negative. Therefore, the  formulae are traditionally presented as

Magnifying glass
The maximum angular magnification (compared to the naked eye) of a magnifying glass depends on how the glass and the object are held, relative to the eye. If the lens is held at a distance from the object such that its front focal point is on the object being viewed, the relaxed eye (focused to infinity) can view the image with angular magnification

Here,  is the focal length of the lens in centimeters. The constant 25 cm is an estimate of the "near point" distance of the eye—the closest distance at which the healthy naked eye can focus. In this case the angular magnification is independent from the distance kept between the eye and the magnifying glass.

If instead the lens is held very close to the eye and the object is placed closer to the lens than its focal point so that the observer focuses on the near point, a larger angular magnification can be obtained, approaching

A different interpretation of the working of the latter case is that the magnifying glass changes the diopter of the eye (making it myopic) so that the object can be placed closer to the eye resulting in a larger angular magnification.

Microscope
The angular magnification of a microscope is given by

where  is the magnification of the objective and  the magnification of the eyepiece. The magnification of the objective depends on its focal length  and on the distance  between objective back focal plane and the focal plane of the eyepiece (called the tube length):

The magnification of the eyepiece depends upon its focal length  and is calculated by the same equation as that of a magnifying glass (above).

Note that both astronomical telescopes as well as simple microscopes produce an inverted image, thus the equation for the magnification of a telescope or microscope is often given with a minus sign.

Telescope
The angular magnification of an optical telescope is given by

in which  is the focal length of the objective lens in a refractor or of the primary mirror in a reflector, and  is the focal length of the eyepiece.

Measurement of telescope magnification
Measuring the actual angular magnification of a telescope is difficult, but it is possible to use the reciprocal relationship between the linear magnification and the angular magnification, since the linear magnification is constant for all objects.

The telescope is focused correctly for viewing objects at the distance for which the angular magnification is to be determined and then the object glass is used as an object the image of which is known as the exit pupil. The diameter of this may be measured using an instrument known as a Ramsden dynameter which consists of a Ramsden eyepiece with micrometer hairs in the back focal plane. This is mounted in front of the telescope eyepiece and used to evaluate the diameter of the exit pupil. This will be much smaller than the object glass diameter, which gives the linear magnification (actually a reduction), the angular magnification can be determined from

Maximum usable magnification
With any telescope or microscope, or a lens
a maximum magnification exists beyond which the image looks bigger but shows no more detail.  It occurs when the finest detail the instrument can resolve is magnified to match the finest detail the eye can see.  Magnification beyond this maximum is sometimes called "empty magnification".

For a good quality telescope operating in good atmospheric conditions, the maximum usable magnification is limited by diffraction.  In practice it is considered to be 2× the aperture in millimetres or 50× the aperture in inches; so, a  diameter telescope has a maximum usable magnification of 120×.

With an optical microscope having a high numerical aperture and using oil immersion, the best possible resolution is  corresponding to a magnification of around 1200×. Without oil immersion, the maximum usable magnification is around 800×.  For details, see limitations of optical microscopes.

Small, cheap telescopes and microscopes are sometimes supplied with the eyepieces that give magnification far higher than is usable.

The maximum relative to the minimum magnification of an optical system is known as zoom ratio.

"Magnification" of displayed images

Magnification figures on pictures displayed in print or online can be misleading.  Editors of journals and magazines routinely resize images to fit the page, making any magnification number provided in the figure legend incorrect. Images displayed on a computer screen change size based on the size of the screen.  A scale bar (or micron bar) is a bar of stated length superimposed on a picture. When the picture is resized the bar will be resized in proportion.  If a picture has a scale bar, the actual magnification can easily be calculated.  Where the scale (magnification) of an image is important or relevant, including a scale bar is preferable to stating magnification.

See also
 Lens
 Magnifying glass
 Microscope
 Optical telescope
 Screen magnifier

References

Optics
Articles containing video clips

Magnification