Comparison Panasonic KX-TG6821 vs Panasonic KX-TG2511

— Android. The phone is running a full Android mobile operating system, created by Google specifically for smartphones and tablet computers. On the one hand, such models perform all the features of a conventional radiotelephone — using the base, the device connects to the telephone network and allows you to make calls to landline numbers, there is a caller ID, answering machine and address book. On the other hand, the device looks like a modern smartphone and has all of its features (sending SMS messages, accessing the Internet, making video calls, listening to music or watching movies, using many different applications and games available through the proprietary Google Play service).

— Answering machine. A device that allows you to receive an incoming call and save a message from the caller if the user is not near the phone at the time of the call or he cannot (or does not want to) pick up the phone. The answering machine turns on if the user does not pick up the handset for a while when an incoming call arrives (a specific turn-on time can be pre-configured). A pre-recorded greeting message is read to the subscriber on the line, usually approximately as follows: “Hello, you called ... (user's first or last name). Unfortunately, I am unable to answer the phone at the moment. Leave your message after the beep”, after which the recording mode is activated and the caller can leave a voice message (for e...xample, introduce himself and ask to call back). Thus, the presence of an autoresponder significantly reduces the likelihood of missing important information. It should be noted that the inclusion of the answering machine occurs with the establishment of a connection, which accordingly affects the billing of the call for the subscriber on the line.

— Caller ID. This is a device that, when an incoming call is received on the phone, requests the number of the caller and displays it on the phone display. Similar to an answering machine, caller ID activation occurs with the actual establishment of a connection, the call fee begins to accrue from this moment, and the user on the line learns about caller ID activation due to a characteristic change in the tone of the dial tone.

— Autodial. This feature allows you to automatically dial a specific number until the other end of the line answers. It is especially useful in cases where the desired number is constantly busy: instead of manually dialing the desired number and manually resetting the call each time the line is busy, the user just needs to set the number and turn on auto redial. Some models may provide additional options for this feature — for example, choosing the interval between attempts to get through or limiting the number of these attempts. In this case, usually, there is no need to hold the handset to your ear — if the connection is successful, the phone will turn on the speakerphone (after which you can turn it off and talk through the handset).

— Caller ID. The CLIP FSK Caller ID standard is an analogue of Caller ID (see Caller ID) used on digital exchanges. It differs, in particular, in that the identification of the number using the Caller ID protocol occurs without establishing a connection.

— Speed Dial. A feature that makes it easier to dial the most frequently used phone numbers. In telephones with speed dialing, such numbers can be stored in the handset or base; each of them will be assigned a sequence number (one-, two- or three-digit), after which telephone numbers can be dialed automatically by simply entering the corresponding sequence number on the keypad.

— Emergency call. A special phone mode, designed primarily for children who do not know how to dial telephone numbers. The phone switched on in this mode automatically dials the previously entered number when pressing any button on the keypad; it may also turn on the speakerphone. Thus, the child left at home will be able, if necessary, to get through to the parents without any problems.

— Bluetooth. The Bluetooth standard is used for wireless communication between various devices over short distances (up to 10 m); however, the devices do not have to be in direct line of sight with each other. In radiotelephones, the Bluetooth module can be used, for example, to connect to a computer or laptop: in this way, you can edit or synchronize the address book, download new ringtones, work with answering machine entries, etc.

— Intercom (internal communication). Possibility of two-way voice communication, usually between handset and base (or handset and handset). In this case, the call "to communicate" can, usually, be sent both from the handset and from the base. Communication in this mode uses only the channel between the handset and the base and does not occupy the telephone line, so there is no risk of missing an external incoming call during such negotiations. This feature can be especially useful if the handset and base are separated by a considerable distance. Another type of intercom is the ability to communicate between separate handsets connected to the same base. This feature is also referred to as "Walkie-Talkie Mode"; see the corresponding glossary item for more details.

— Conference call. Possibility of simultaneous conversation between several people. This can be either a purely “internal” conversation (for example, a user at a base with two users connected to it with handsets, see “Intercom (intercom)”), or a conversation involving an external subscriber on the line. At the same time, phones with conference support usually allow you to turn on this mode after receiving an external call — after answering the call, you can call the user at another handset / base and conduct a simultaneous conversation between three subscribers. This mode is very convenient for organizing meetings.

— Speakerphone. In hands-free mode, the person's voice on the line is reproduced through a special speaker, and the your voice is perceived through a special microphone (such a speaker and microphone can be located both on the handset and on the base of the phone). At the same time, the loudspeaker volume is high enough, and the microphone is sensitive enough so that a conversation can be carried out without bringing the handset to your ear (as an option, without removing it from the base at all). Thus, when the speakerphone is turned on, everyone present in the room gets the opportunity to participate in the conversation, and the user himself gets rid of the need to hold the handset and can, for example, comfortably take notes.

— Jack for the headset. A connector that allows you to connect a wired headset to the handset of the radiotelephone. This allows you to free your hands during a conversation — for example, put the handset in your pocket and conveniently record dictated information. Note that the specific connection interface in different models may be different: some devices use standard formats like a 3.5 mm mini-jack, while others work only with original plugs.

— Support for SMS messages. The ability to use a radiotelephone to send and receive short text messages (Short Message Service, SMS) — similar to those used in most modern mobile networks. To use this feature, the phone must be connected to a digital fixed telephone network that supports receiving and sending SMS.

— Night mode. Phone operating mode intended for night time or when it is necessary that no one disturbs the user (for example, during the sleep of a small child). In this mode, the sound of the call is completely turned off; while the light indication of an incoming call can be preserved. Night mode can be turned on and off both manually and automatically at a pre-set time.

— Baby monitor mode. This mode allows you to listen to what is happening in the room while being in another room. This can be useful, for example, if a small child is sleeping in the room — the Baby Monitor function will allow you not to miss the moment of his awakening. Typically, two handsets are used for this mode: one is placed in the listening room, the second is carried by the user. When there is noise in the room, the user's handset receives a call; answering it, he can listen to what is currently happening in the room.

— Radio mode. A variation of the intercom mode (see Intercom), in which two-way voice communication is carried out between two handsets, bypassing the connection to the base. Like a regular intercom, such communication is carried out via an internal channel, but an external connection will not be available at this moment.

— Black list. The purpose of this feature is generally clear from the name: it allows you to add certain numbers to the list of unwanted ones. When a call is received from such a number, the phone will block the call without notifying the owner (the subscriber on the other end of the line may receive a busy signal, or the call may be dropped). In this way, you can protect yourself from unwanted calls. And some devices with this function also support the "white list" function. It works the other way around: the phone blocks all numbers except those on the list.

— Blocking the dialing of restricted numbers. Ability to block phone calls to specific numbers. It is technically possible to provide the blocking of any set of numbers, up to a specific phone number; however, blocking by number range or type is much more common. For example, by prohibiting calls to numbers starting with "8", you can block the ability to call from a telephone over long distances and to mobile phones; and if you enter a ban on "8 plus operator code", you can restrict access to specific mobile networks. Usually, the lock is protected by a digital password and can only be disabled after entering a given combination.

GAP(General Access Protocol) is an extension to the DECT standard (see Communication Standard) that provides compatibility between handsets and bases from different manufacturers. Thus, handsets supporting this standard can be easily connected to a base with GAP support, regardless of whether they are from the same bundle or not, whether they are made by the same manufacturer or by another — the main features of the phone, such as dialing and talking, will be available to the user anyway. At the same time, GAP support does not guarantee the possibility of using additional features (for example, managing an answering machine). Also, the GAP protocol allows you to connect several handsets to one base at the same time and vice versa, one handset to several bases.

The number of bases to which a radiotelephone handset can be simultaneously connected using GAP technology (see above).

Connecting to multiple bases can be useful when you have to deal with several phone numbers, and the call to be answered can come from any of them. At the same time, the real need for such a mode of operation is very rare, so modern handsets rarely support more than one base (and in many GAP-compatible models this parameter is not indicated at all).

The amount of numbers that can be stored in the phone's own address book. The presence of such an address book eliminates the need to remember frequently used phone numbers, eliminates the need for paper telephone directories and greatly simplifies the process of dialing — just select it in the phone book and press the call button.

The number of ringtones stored in the phone's memory. The bigger the number of melodies, the wider the user's options to choose the melody to his liking.

The amount of recent outgoing calls that can be stored in the phone's memory at one time. The presence of a log of outgoing calls allows you to control which numbers were called from this phone, as well as use the re-dial function (re-dial), which eliminates the need to manually dial the number again — usually just select the corresponding number in the list and press the call button.

Alarm clock feature of the phone: at the time specified by the user, the device beeps, which allows, for example, to wake up on time.

The backlighting of the phone's keys makes it easier to manage it (in particular, dialing) in low light conditions, in which it would be quite problematic to figure out the unlit characters on the buttons.

The maximum time of operation of the handset on one full charge of the battery in talk mode. Long talk time will be relevant for those who expect to regularly conduct long telephone conversations.