Silta RCS clients


Neusoft Silta RCS clients are available for Android handsets/tablets (version 4.0 and beyond), iOS handsets/tablets (version 7.0 and beyond) and PC/Mac devices.

Windows Phone, Blackberry, Jolla and other platfroms are supported based on customer requirements.

Silta clients are natively embedded to mobile operating system UI and also offer an intuitive standalone and customizable app UI. The client is fully localizable and customizable to the Operator look & feel.

The most common delivery method for the clients are the Application Stores, but also other delivery and distribution methods are possible based on customer requirements.

Download the White Paper and Solution Description here.



Enhanced Address Book

The Silta application enhances the native phonebook by adding quick access to RCS feature for all RCS capable native contacts. This allows RCS feature to be used directly from the native phonebook. The application contact list also offers an enhanced contact list that contains all native contacts. The application address book has more emphasis on RCS features while still providing the traditional CS services such as phone call and SMS

Network Address Book

Silta clients support use of a Network Address Book server (S-CAB based or HTTP based) to import and export contacts and synchronize contacts between the different devices of the user.
The user can also use any contact import/synch method available on his devices to place contacts from other sources (such as Outlook or Google Contacts) to the network address book.

Capability discovery

For all RCS features, Silta client adopt the RCS based capability discovery mechanism to identify which contacts are RCS capable and what feature can be used for each contact. Silta clients support capability discovery using both SIP Options and Presence based discovery. This allows a broader interworking with other clients.

1-to-1 chat

Neusoft Silta clients offers advanced SIP SIMPLE and CPM based Instant messaging features, including

  • message delivery notifications
  • is typing notifications
  • local chat history 
  • central message store
  • store&forward functionality support
  • native notifications of incoming messages
  • multi-device support
  • recent messages timeline
  • unread message counters.

Group chat

The group chat features of the Silta clients covers the same features as 1-to-1 chat. In addition it offers the following:

  • Adding new group members
  • Re-joining and restarting group chats automatically when needed
  • Viewing group members info (availability)

Standalone Messaging

Standalone messaging is pushed by operators as the next technology for SMS/MMS messages. Silta clients support Standalone Messaging for 1-to-1 chat and group chat, both for SIMPLE-IM and CPM protocols. Using Silta clients with Standalone Messaging features makes it easy to integrate all SMS, MMS and RCS messaging in the network.

Audio Messaging

Audio messaging is a form of audio messaging, where users can send each other voice messages by just holding and releasing a recording button in the Messaging UI. The recorded audio is sent to the recipient who can playback the message in his own client.

File share

Silta clients support MSRP and HTTP based sharing of any type of file (pictures, videos, camera images, music, movies, documents, etc) during 1-to-1 or group chat conversations or during calls (image share). File Transfer features include compression, large size warnings, real-time transfer progress indication, cancelling and resending. The max sizes of allowed file shares are fully configurable by the operator.

Contact Share

The Contact share feature allows users to share contact details to other users with standardized VCard formats, according the RCS specification. This allows sharing of contact details (phone numbers, name, addresses) between mobile and desktop users, regardless of what operating system they use.
With Silta clients, the contact share is directly available in the messaging share function and is also available when opening any contact in with the Silta client.

Location Share

The Geolocation feature is supported by Silta as a RCS 5 Location Push. This feature is available during chat or calls and uses the native maps application to pinpoint the user with GPS. The user can also opt to pan the map to another location and share this location. Location share features in Silta clients include geolocation of user with GPS, geocoding of location into an address, adding a textual description to a shared location, native notifications of incoming location share and location share history.

The Silta client also offers a built in navigation feature for any received location share. Whenever a user receives a location share, it’s possible to show the route from the user current location to the received location. The user will get detailed navigational instruction how to get there.

Video Share

During 1-to-1 calls, Silta clients offer the user the possibility to activate the phone camera and share a live feed to the callee. The video share can also be bi-directional when activated on both sides. Video share is available in both 3G and Wifi, but the Silta clients offer a premium quality resolution when used over Wifi or 4G. Video share feature include flexible macro-block ordering, arbitrary slice ordering and redundant slice support. Supported base codec is H.264 level 1b and others are available on request (e.g. VP8).

Image Share

During calls, Silta clients also offer a possibility to activate the camera and send a snapshot, or to select an image and share that with the recipient. The Image share features are supported according to RCS 5 and joyn Blackbird specifications.


Neusoft Silta clients offer a comprehensive RCS 5.1 based presence feature add-on on top of the RCS feature set. The presence feature additionally enhances the contact list with presence information and also allows capability exchange to be done with presence instead of SIP Options.

Voice over IP

Building on its SIP based architecture the Silta clients also offers extensive RCS 5.1 VoIP and Video calling features. VoIP calls can be launched from a chat conversation or from a contact card. VoIP features include ringtones, volume level control, microphone muting, loudspeaker activation, proximity sensor, call length display, native notification for incoming VoIP calls, phone key-lock control and VoIP call history.

Supported base codec is AMR Wideband and others are available on request (e.g. SILK, OPUS, and G.711). VoIP call quality is ensured by use of Jitter buffer and Qos&Tos tags in packets. NAT traversal is supported by STUN and symmetric RTP/RTCP.

Video over IP

Silta clients also support Video over IP sessions according to joyn Blackbird specification. Live video can also be added and removed to ongoing IP call sessions. Supported codecs are H.264 and VP8.

Multi-device support

Silta apps support full multi-device functionality, when the same user has multiple devices registered to the same MSISDN. The Multi-Device feature includes:

  • chat and Call invite forking to all registered devices
  • message sync between devices
  • contact sync between devices
  • RCS 5 based GRUU and sip-instance methods
  • RCS 5 Message store functionality