Call for me is different than for staff attendings (real doctors). Because I'm a resident, I function as a doctors eyes/ears, essentially, so they can stay at home and advise over the phone for an appropriate care of action. Essentially, staff doctors function as our "backup" for day-to-day issues, and we run by our care plan and addmissions by them for all new admissions.
Our requirements are 26 hours direct patient care maximum, and we are paid about $175 or so for a weekend 26 hr block. The maximum you can be on call is 1:4 on average in a month (which means you are on call every 4 days, ie: Monday call, Tuesday sleep, Wed regular ward duties, Thursday call).
We have to answer our pages ASAP - generally I try to answer < 5 minutes, and we can have up to 2 hrs to respond in person in a hospital, if we are on home call. We have rapid pagers as well, and when those go off you're expected to be in hospital ASAP. There are also code pagers for STAT response, but luckily, I don't have to carry a code pager.
In addition, we are expected to teach the medical students who are on call with us, as well as any other individuals from other professions (sometimes we get EMS, nursing, etc who want to come along for call).
Right now, we are responsible for all the patients on three medical wards, and the emergency department if they are admitted to us and awaiting a bed on the ward. We are additionally responsible for "consultation" to see the ER patients whom the ER doctor feels should be assessed, or any inpatients who may require additional help.
Hope that helps
ETA: Thistle, what your paediatrician has is "outpatient" call. What I have described above is inpatient call Outpatient docs always have "send to ER" as an option, and then they become the responsibility of the doc on inpatient call, if deemed necessary by ER doc (who work shifts).
ETA#2: I am a resident at a teaching hospital - so our staff attendings have us to help them out on call! Most of them are very lovely and will come to the hospital if we need them to, and sometimes their billing is different if they see the patients vs. review on them on the phone. There are also "physician extenders" who function as residents but are full GP's who work as "eyes and ears" of specialties - they bill about $1000/24 hr period.