Life Safety and Emergencies
A building with a DAS can increase the safety of the building's occupants. During an emergency the DAS will enable 911 calls within the building. The multiple antennas in a DAS will provide improved communication reliability, and provide communications with First Responders, police, and fire fighters. Note that two national fire codes, the National Fire Protection Association's NFPA-1 and the International Fire Code were enacted in 2009 require in-building amplification systems such as a DAS. Such codes have been adopted in municipalities across the country.
The Federal Communications Commission (FCC) is responsible for ensuring that 911 services and other critical communications remain operational during emergencies. This includes ensuring communications interoperability among first responders and promoting use of enhanced 911 best practices. One of the main components is 911 call processing and delivery through public safety answering points (PSAP).
At the PSAP, the dispatcher verifies the caller's location, determines the nature of the emergency, and decides which emergency response teams should be notified. However, the use of cell phones makes determining a wireless 911 caller's location more complicated than determining a traditional wireline 911 caller's location (where numbers are associated with a fixed address.) For callers placing wireless 911 calls, the FCC has required wireless service providers to make location information automatically available to public-safety answering point (PSAPs). Basic 911 rules require wireless service providers to transmit all 911 calls to a PSAP, regardless of whether the caller subscribes to the provider's service or not. The wireless service providers have to provide the PSAP with the telephone number of the originator of a wireless 911 call and the location of the cell site or base station transmitting the call. Eventually wireless service providers will be required to provide more precise location information to PSAP.
Emerging DAS systems can deploy a self-organizing network (SON). The self-organizing network can:
- (a) Automatically configure and integrate new equipment into the wireless network, something akin to plug and play. The network also discovers new components in a system without the need for a technician to manually reconfigure the equipment.
- (b) Automatically optimize the wireless network. It optimizes based on data from the system itself. An example of self-optimization is the automatic switch-off of a percent of base stations during the night which would reconfigure to cover a larger area or a significant increase in usage.
- (c) Self-heal, where the network can identify faults or failures in the network such as, base station failure. The network compensates and reconfigures to minimize the impact.
The DAS network can now move cell capacity from one location to another needing capacity, as well as identify what radio spectrums and functionality are needed on-demand in real-time. While all manner of base stations will be used in future network deployments, DAS will play a central role in providing on-demand capacity wherever and whenever it is needed.
While distributed antennas systems are primarily focused on large venues and buildings, there are smaller cells available for more modest spaces and buildings. These cells are called micro cells, pico cells, or femto cells. They are small mobile phone base stations that are connected to the wireless carrier's network via the Internet and typically used in areas where the mobile signal is weak. Generally these are very low-range, low-power base stations, able to be deployed in a home, home office, enterprise businesses, indoor or outdoor public space. Generally the equipment is provided by a wireless carrier mobile network operator, and operates in licensed frequency bands. A base station in a wireless carrier's network may have a radius of 2-30 km coverage; the small cells may have coverage radius of 10 meters.