Mobile Voice & Paging | Services

Mobile Voice

The most well known application for wireless communications is voice communications. Voice communication can be telephony; wide area (cellular), business location (wireless office) or home cordless (residential) or voice paging, dispatch (fleet coordination) or group voice (audio broadcasting). Service rates for voice applications typically involve an initial connection charge, basic monthly minimum fee, plus an airtime usage charge. When the customer uses service in another system than their home registered system, there may be a daily fee and/or a higher per minute usage fee.

Figure 1 shows that mobile telephone charges include recurring costs and usage costs. Mobile telephone systems also offer advanced features. In many cases, the advanced features are offered for free (e.g., voice mail) as they increase usage costs.

Figure 1: Mobile Telephone Costs

Paging

Paging services include tone paging, numeric paging, alpha (text) paging, and voice paging. Tone paging service notifies a paging customer that a message has been sent via a tone. This tone usually is designated to mean a callback to a single location is requested. The original “beep, beep” tone pagers that started it all have become very popular as entry-level private communications systems, including restaurants (beeping servers when orders are ready) and in other centralized locations where a tone page necessitates a choice in response to only one.

While the popularity of these types of pagers has decreased overall, some retailers continue to offer tone pagers as “loss leaders” allowing the publication of low prices in print ads to attract attention. Still, for dispatch operators or other industries that only need a response to a central office, tone pagers offer a cost-effective solution.

Numeric paging is the sending of paging messages, typically telephone numbers that are displayed on a small paging device. After the message is received, the user calls back the displayed telephone number to talk to the sender.

Figure 2 shows that the typical cost for numeric paging service typically involves signing up for local, regional, or nationwide coverage. Rate plans start with a monthly service charge that allows pages using a local telephone number. Additional charges may be assessed for 800 toll free and 0800 freephone access numbers. Paging carriers usually offer a maximum number of pages per month and pages that additional per-page charges may apply for pages that are sent beyond the pre-defined limit.

Figure 2: Paging Cost

Alpha paging displays numerical and textual information. This can take many forms, from verbatim text messages to weather reports. Messages can be recorded into voice mail where operators type them up and send them out, or callers can dictate messages to live operators directly. Many carriers bundle free news, weather and sports feeds from other sources. While some carriers offer unlimited numeric usage, many charge for additional pages (both numeric and text message) beyond a pre-defined limit. Some carriers charge so much per character while others simply charge by the message.

Voice pagers broadcast messages through a built-in speaker in the paging unit. Message volume settings can usually be set to loud, soft or private, through an earpiece.

Two-way pagers allow fully interactive capabilities, permitting users to respond to pages by sending an original or canned alphanumeric message. Additional hardware must be purchased (or leased). Customers can lease the paging device for about $15 per month or purchase it for around $399.00.

Paging (Wireless Networks)

Paging
Paging is a method of delivering a message, via a public or private communications system or radio signal, to a person whose exact whereabouts are unknown. Users as a rule carry a small paging receiver that displays a numeric or alphanumeric message displayed on an electronic readout or it could be sent and received as a voice message or other data.

Commercial paging service began in 1949 with the allocation of frequencies exclusively dedicated to one-way signaling services. Subscribers used AM receivers, listened for an operator to announce their number, and then called the service to receive their messages. Selective addressing (the ability to choose one individual pager from the group) was introduced in the mid 1950’s and FM was first used in an experimental paging system in 1960. Pagers with alphanumeric displays made their debut in the early 1990’s. In addition to complete messages that can be sent and stored in these pagers, a number of other services such as stock market and sports score reporting have been developed.

There are 4 basic types of messaging services offered by paging systems: tone, numeric, text (alpha), and voice. Two types of paging systems can deliver these messaging services: one-way and two-way paging. One-way paging systems only allow the sending of messages from the system to the pager. Two-way paging systems allow the confirmation and response of a message from the pager to the system as well.

One-way paging is a process where paging messages (signals) are sent from a radio tower to a pager without a return verification signal. In its simplest form, a one-way paging system can serve up to several hundred thousand numeric paging customers.

Figure 1 shows a one-way paging system. In this diagram, a high-power transmitter broadcasts a paging message to a relatively large geographic area. All pagers that operate on this system listen to all the pages sent, paying close attention for their specific address message. Paging messages are received and processed by a paging center. The paging center receives pages from the local telephone company or it may receive messages from a satellite network. After it receives these messages, they are sent after processing to the high-power paging transmitter by an encoder. The encoder converts the pagers telephone number or identification code entered by the caller to the necessary tones or digital signal to be sent by the paging transmitter.


Figure 1: One-Way Paging System
Two-way paging systems allow the paging device to acknowledge and sometimes respond to messages sent by a nearby paging tower. The two-way pager’s low-power transmitter necessitates many receiving antennas being located close together to receive the low-power signal.

Figure 2 shows a high-power transmitter (200-500 Watts) which broadcasts a paging message to a relatively large geographic area and several receiving antennas. The reason for having multiple receiving antennas is that the transmit power level of pagers are much lower than the transmit power level of the paging radio tower. The receiving antennas are very sensitive, capable of receiving the signal from pagers transmitting only 1 watt.


Figure 2: Two-Way Paging System
The number of required receivers for a two-way paging system is dependent on the available transmittal power from the paging and how fast the information is to be transferred. The higher the data transmission rate results in a higher number of required receivers.

The main advantage of two-way paging systems is their ability to require pagers to register their location within the paging system. This allows the paging system to direct pages for a specific pager only to the area near where the pager last registered. This frees up the paging capacity of channels in other geographic areas so paging messages can be sent to other pagers. This is a type of frequency reuse based on geographically separated systems.

Wireless Networks

Wireless networks are primarily designed to transfer voice and or data from one point to one or more other points, (multipoint). Many networks make use of some wireless technologies as a transport medium even though we do not consider them to be wireless networks. Examples of wireless networks include cellular, personal communication service, (PCS), paging, wireless data, satellite, and broadcast radio and television.

Cellular and PCS
Cellular and PCS systems are comprised of a set of radio towers that are strategically distributed over a geographical area in order to provide a continuous service coverage area. A mobile switching center (MSC) provides the switching and control functions necessary to connect calls from the public switched telephone network (PSTN) to the individual mobile telephones. The MSC also manages the radio resources within the entire network.

Several service providers (carriers) within a particular geographical area can provide wireless services simultaneously as long as they use a different set of radio frequencies that do not interfere with each other. Specific sets of radio frequencies are allocated for use in cellular communications systems. Typically a government agency is responsible for assigning these frequencies and licensing them to specific service providers.

Paging
Paging is a wireless system that is capable of delivering message to one or more people whose exact whereabouts are unknown by the sender of the message. Users typically carry a small paging receiver that displays a numeric or alphanumeric message displayed on an electronic readout. It also could be sent and received as voice message or other data. Pager systems may be classified based upon their capabilities as numeric, alphanumeric, tone, or voice.

Paging networks are comprised of terrestrial based antennas all interconnected by means of some other type of physical network. Satellite transmission systems are often used to distribute the messages to multiple towers for retransmission. The use of satellite interconnection systems permits regional, nationwide, or global paging service. Some paging systems are capable of providing two-way communications.

Each pager in the network has a unique identifier (address) that is stored to the pager’s memory. This address is also stored in the paging network. When an incoming telephone call accesses the pager customer’s account, the network transmits the address of the pager on its radio tower. In addition to sending a specific paging address, the system may send other digits, text, or even voice information that follows the addressing message.

Wireless Data
Wireless data networks transfer data between network access points (wireless data devices) through radio transmission and are primarily designed to transfer data from one point to one or more points (multipoint). These networks may be composed of a variety of communication systems including: mobile data terminals, radio access nodes, packet switching networks. Wireless data networks provide a variety of services including: equipment status monitoring, dispatch services, vehicle and goods tracking, credit card validation, and include wireless Internet access.

Broadcast
Broadcasting is a process that sends voice, data, or video signals simultaneously to group of people or companies in a specific geographic area or who are connected to the broadcast network system (e.g., satellite or cable television system). It is typically associated with radio or television radio transmission systems that send the same radio signal to many receivers in a geographic area. Broadcasting can also be applied to wired distribution or point-to-point networks where all users that are connected to the network can receive the same information signal.

Figure below shows the different types of wireless networks. This diagram shows a private land mobile radio system, television broadcast system, paging system, mobile telephone system, and satellite communication system. Although all wireless networks can transmit information from one point to another, different types of networks better suited to provide specific types of services (e.g., paging compared to television broadcasting).


Wireless Networks